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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3.time;
18  
19  import java.text.ParseException;
20  import java.text.ParsePosition;
21  import java.time.LocalDateTime;
22  import java.time.OffsetDateTime;
23  import java.time.ZoneId;
24  import java.time.ZonedDateTime;
25  import java.util.Calendar;
26  import java.util.Date;
27  import java.util.Iterator;
28  import java.util.Locale;
29  import java.util.NoSuchElementException;
30  import java.util.Objects;
31  import java.util.TimeZone;
32  import java.util.concurrent.TimeUnit;
33  
34  import org.apache.commons.lang3.LocaleUtils;
35  
36  /**
37   * A suite of utilities surrounding the use of the
38   * {@link java.util.Calendar} and {@link java.util.Date} object.
39   *
40   * <p>DateUtils contains a lot of common methods considering manipulations
41   * of Dates or Calendars. Some methods require some extra explanation.
42   * The truncate, ceiling and round methods could be considered the Math.floor(),
43   * Math.ceil() or Math.round versions for dates
44   * This way date-fields will be ignored in bottom-up order.
45   * As a complement to these methods we've introduced some fragment-methods.
46   * With these methods the Date-fields will be ignored in top-down order.
47   * Since a date without a year is not a valid date, you have to decide in what
48   * kind of date-field you want your result, for instance milliseconds or days.
49   * </p>
50   * <p>
51   * Several methods are provided for adding to {@link Date} objects, of the form
52   * {@code addXXX(Date date, int amount)}. It is important to note these methods
53   * use a {@link Calendar} internally (with default time zone and locale) and may
54   * be affected by changes to daylight saving time (DST).
55   * </p>
56   *
57   * @since 2.0
58   */
59  public class DateUtils {
60  
61      /**
62       * Date iterator.
63       */
64      static final class DateIterator implements Iterator<Calendar> {
65          private final Calendar endFinal;
66          private final Calendar spot;
67  
68          /**
69           * Constructs a DateIterator that ranges from one date to another.
70           *
71           * @param startFinal start date (inclusive).
72           * @param endFinal end date (inclusive).
73           */
74          DateIterator(final Calendar startFinal, final Calendar endFinal) {
75              this.endFinal = endFinal;
76              spot = startFinal;
77              spot.add(Calendar.DATE, -1);
78          }
79  
80          /**
81           * Has the iterator not reached the end date yet?
82           *
83           * @return {@code true} if the iterator has yet to reach the end date.
84           */
85          @Override
86          public boolean hasNext() {
87              return spot.before(endFinal);
88          }
89  
90          /**
91           * Returns the next calendar in the iteration.
92           *
93           * @return Object calendar for the next date.
94           */
95          @Override
96          public Calendar next() {
97              if (spot.equals(endFinal)) {
98                  throw new NoSuchElementException();
99              }
100             spot.add(Calendar.DATE, 1);
101             return (Calendar) spot.clone();
102         }
103 
104         /**
105          * Always throws UnsupportedOperationException.
106          *
107          * @throws UnsupportedOperationException Always thrown.
108          * @see java.util.Iterator#remove()
109          */
110         @Override
111         public void remove() {
112             throw new UnsupportedOperationException();
113         }
114     }
115 
116     /**
117      * Calendar modification types.
118      */
119     private enum ModifyType {
120 
121         /**
122          * Truncation.
123          */
124         TRUNCATE,
125 
126         /**
127          * Rounding.
128          */
129         ROUND,
130 
131         /**
132          * Ceiling.
133          */
134         CEILING
135     }
136 
137     /**
138      * Number of milliseconds in a standard second.
139      *
140      * @since 2.1
141      */
142     public static final long MILLIS_PER_SECOND = 1_000;
143 
144     /**
145      * Number of milliseconds in a standard minute.
146      *
147      * @since 2.1
148      */
149     public static final long MILLIS_PER_MINUTE = 60 * MILLIS_PER_SECOND;
150 
151     /**
152      * Number of milliseconds in a standard hour.
153      *
154      * @since 2.1
155      */
156     public static final long MILLIS_PER_HOUR = 60 * MILLIS_PER_MINUTE;
157 
158     /**
159      * Number of milliseconds in a standard day.
160      *
161      * @since 2.1
162      */
163     public static final long MILLIS_PER_DAY = 24 * MILLIS_PER_HOUR;
164 
165     /**
166      * This is half a month, so this represents whether a date is in the top
167      * or bottom half of the month.
168      */
169     public static final int SEMI_MONTH = 1001;
170     private static final int[][] fields = {
171             {Calendar.MILLISECOND},
172             {Calendar.SECOND},
173             {Calendar.MINUTE},
174             {Calendar.HOUR_OF_DAY, Calendar.HOUR},
175             {Calendar.DATE, Calendar.DAY_OF_MONTH, Calendar.AM_PM
176                 /* Calendar.DAY_OF_YEAR, Calendar.DAY_OF_WEEK, Calendar.DAY_OF_WEEK_IN_MONTH */
177             },
178             {Calendar.MONTH, SEMI_MONTH},
179             {Calendar.YEAR},
180             {Calendar.ERA}};
181 
182     /**
183      * A week range, starting on Sunday.
184      */
185     public static final int RANGE_WEEK_SUNDAY = 1;
186 
187     /**
188      * A week range, starting on Monday.
189      */
190     public static final int RANGE_WEEK_MONDAY = 2;
191 
192     /**
193      * A week range, starting on the day focused.
194      */
195     public static final int RANGE_WEEK_RELATIVE = 3;
196 
197     /**
198      * A week range, centered around the day focused.
199      */
200     public static final int RANGE_WEEK_CENTER = 4;
201 
202     /**
203      * A month range, the week starting on Sunday.
204      */
205     public static final int RANGE_MONTH_SUNDAY = 5;
206 
207     /**
208      * A month range, the week starting on Monday.
209      */
210     public static final int RANGE_MONTH_MONDAY = 6;
211 
212     /**
213      * Adds to a date returning a new object.
214      * The original {@link Date} is unchanged.
215      *
216      * @param date  the date, not null.
217      * @param calendarField  the calendar field to add to.
218      * @param amount  the amount to add, may be negative.
219      * @return the new {@link Date} with the amount added.
220      * @throws NullPointerException if the date is null.
221      */
222     private static Date add(final Date date, final int calendarField, final int amount) {
223         validateDateNotNull(date);
224         final Calendar c = Calendar.getInstance();
225         c.setTime(date);
226         c.add(calendarField, amount);
227         return c.getTime();
228     }
229 
230     /**
231      * Adds a number of days to a date returning a new object.
232      * The original {@link Date} is unchanged.
233      *
234      * @param date  the date, not null.
235      * @param amount  the amount to add, may be negative.
236      * @return the new {@link Date} with the amount added.
237      * @throws NullPointerException if the date is null.
238      */
239     public static Date addDays(final Date date, final int amount) {
240         return add(date, Calendar.DAY_OF_MONTH, amount);
241     }
242 
243     /**
244      * Adds a number of hours to a date returning a new object.
245      * The original {@link Date} is unchanged.
246      *
247      * @param date  the date, not null.
248      * @param amount  the amount to add, may be negative.
249      * @return the new {@link Date} with the amount added.
250      * @throws NullPointerException if the date is null.
251      */
252     public static Date addHours(final Date date, final int amount) {
253         return add(date, Calendar.HOUR_OF_DAY, amount);
254     }
255 
256     /**
257      * Adds a number of milliseconds to a date returning a new object.
258      * The original {@link Date} is unchanged.
259      *
260      * @param date  the date, not null.
261      * @param amount  the amount to add, may be negative.
262      * @return the new {@link Date} with the amount added.
263      * @throws NullPointerException if the date is null.
264      */
265     public static Date addMilliseconds(final Date date, final int amount) {
266         return add(date, Calendar.MILLISECOND, amount);
267     }
268 
269     /**
270      * Adds a number of minutes to a date returning a new object.
271      * The original {@link Date} is unchanged.
272      *
273      * @param date  the date, not null.
274      * @param amount  the amount to add, may be negative.
275      * @return the new {@link Date} with the amount added.
276      * @throws NullPointerException if the date is null.
277      */
278     public static Date addMinutes(final Date date, final int amount) {
279         return add(date, Calendar.MINUTE, amount);
280     }
281 
282     /**
283      * Adds a number of months to a date returning a new object.
284      * The original {@link Date} is unchanged.
285      *
286      * @param date  the date, not null.
287      * @param amount  the amount to add, may be negative.
288      * @return the new {@link Date} with the amount added.
289      * @throws NullPointerException if the date is null.
290      */
291     public static Date addMonths(final Date date, final int amount) {
292         return add(date, Calendar.MONTH, amount);
293     }
294 
295     /**
296      * Adds a number of seconds to a date returning a new object.
297      * The original {@link Date} is unchanged.
298      *
299      * @param date  the date, not null.
300      * @param amount  the amount to add, may be negative.
301      * @return the new {@link Date} with the amount added.
302      * @throws NullPointerException if the date is null.
303      */
304     public static Date addSeconds(final Date date, final int amount) {
305         return add(date, Calendar.SECOND, amount);
306     }
307 
308     /**
309      * Adds a number of weeks to a date returning a new object.
310      * The original {@link Date} is unchanged.
311      *
312      * @param date  the date, not null.
313      * @param amount  the amount to add, may be negative.
314      * @return the new {@link Date} with the amount added.
315      * @throws NullPointerException if the date is null.
316      */
317     public static Date addWeeks(final Date date, final int amount) {
318         return add(date, Calendar.WEEK_OF_YEAR, amount);
319     }
320 
321     /**
322      * Adds a number of years to a date returning a new object.
323      * The original {@link Date} is unchanged.
324      *
325      * @param date  the date, not null.
326      * @param amount  the amount to add, may be negative.
327      * @return the new {@link Date} with the amount added.
328      * @throws NullPointerException if the date is null.
329      */
330     public static Date addYears(final Date date, final int amount) {
331         return add(date, Calendar.YEAR, amount);
332     }
333 
334     /**
335      * Gets a date ceiling, leaving the field specified as the most
336      * significant field.
337      *
338      * <p>For example, if you had the date-time of 28 Mar 2002
339      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
340      * 2002 14:00:00.000.  If this was passed with MONTH, it would
341      * return 1 Apr 2002 0:00:00.000.</p>
342      *
343      * @param calendar  the date to work with, not null.
344      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
345      * @return the different ceil date, not null.
346      * @throws NullPointerException if the date is {@code null}.
347      * @throws ArithmeticException if the year is over 280 million.
348      * @since 2.5
349      */
350     public static Calendar ceiling(final Calendar calendar, final int field) {
351         Objects.requireNonNull(calendar, "calendar");
352         return modify((Calendar) calendar.clone(), field, ModifyType.CEILING);
353     }
354 
355     /**
356      * Gets a date ceiling, leaving the field specified as the most
357      * significant field.
358      *
359      * <p>For example, if you had the date-time of 28 Mar 2002
360      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
361      * 2002 14:00:00.000.  If this was passed with MONTH, it would
362      * return 1 Apr 2002 0:00:00.000.</p>
363      *
364      * @param date  the date to work with, not null.
365      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
366      * @return the different ceil date, not null.
367      * @throws NullPointerException if the date is {@code null}.
368      * @throws ArithmeticException if the year is over 280 million.
369      * @since 2.5
370      */
371     public static Date ceiling(final Date date, final int field) {
372         return modify(toCalendar(date), field, ModifyType.CEILING).getTime();
373     }
374 
375     /**
376      * Gets a date ceiling, leaving the field specified as the most
377      * significant field.
378      *
379      * <p>For example, if you had the date-time of 28 Mar 2002
380      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
381      * 2002 14:00:00.000.  If this was passed with MONTH, it would
382      * return 1 Apr 2002 0:00:00.000.</p>
383      *
384      * @param date  the date to work with, either {@link Date} or {@link Calendar}, not null.
385      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
386      * @return the different ceil date, not null.
387      * @throws NullPointerException if the date is {@code null}.
388      * @throws ClassCastException if the object type is not a {@link Date} or {@link Calendar}.
389      * @throws ArithmeticException if the year is over 280 million.
390      * @since 2.5
391      */
392     public static Date ceiling(final Object date, final int field) {
393         Objects.requireNonNull(date, "date");
394         if (date instanceof Date) {
395             return ceiling((Date) date, field);
396         }
397         if (date instanceof Calendar) {
398             return ceiling((Calendar) date, field).getTime();
399         }
400         throw new ClassCastException("Could not find ceiling of for type: " + date.getClass());
401     }
402 
403     /**
404      * Gets a Calendar fragment for any unit.
405      *
406      * @param calendar the calendar to work with, not null.
407      * @param fragment the Calendar field part of calendar to calculate.
408      * @param unit     the time unit.
409      * @return number of units within the fragment of the calendar.
410      * @throws NullPointerException if the date is {@code null} or fragment is not supported.
411      * @since 2.4
412      */
413     private static long getFragment(final Calendar calendar, final int fragment, final TimeUnit unit) {
414         Objects.requireNonNull(calendar, "calendar");
415         long result = 0;
416         final int offset = unit == TimeUnit.DAYS ? 0 : 1;
417 
418         // Fragments bigger than a day require a breakdown to days
419         switch (fragment) {
420             case Calendar.YEAR:
421                 result += unit.convert(calendar.get(Calendar.DAY_OF_YEAR) - offset, TimeUnit.DAYS);
422                 break;
423             case Calendar.MONTH:
424                 result += unit.convert(calendar.get(Calendar.DAY_OF_MONTH) - offset, TimeUnit.DAYS);
425                 break;
426             default:
427                 break;
428         }
429 
430         switch (fragment) {
431             // Number of days already calculated for these cases
432             case Calendar.YEAR:
433             case Calendar.MONTH:
434 
435             // The rest of the valid cases
436             case Calendar.DAY_OF_YEAR:
437             case Calendar.DATE:
438                 result += unit.convert(calendar.get(Calendar.HOUR_OF_DAY), TimeUnit.HOURS);
439                 // falls-through
440             case Calendar.HOUR_OF_DAY:
441                 result += unit.convert(calendar.get(Calendar.MINUTE), TimeUnit.MINUTES);
442                 // falls-through
443             case Calendar.MINUTE:
444                 result += unit.convert(calendar.get(Calendar.SECOND), TimeUnit.SECONDS);
445                 // falls-through
446             case Calendar.SECOND:
447                 result += unit.convert(calendar.get(Calendar.MILLISECOND), TimeUnit.MILLISECONDS);
448                 break;
449             case Calendar.MILLISECOND: break; //never useful
450                 default: throw new IllegalArgumentException("The fragment " + fragment + " is not supported");
451         }
452         return result;
453     }
454 
455     /**
456      * Gets a Date fragment for any unit.
457      *
458      * @param date the date to work with, not null.
459      * @param fragment the Calendar field part of date to calculate.
460      * @param unit the time unit.
461      * @return number of units within the fragment of the date.
462      * @throws NullPointerException if the date is {@code null}.
463      * @throws IllegalArgumentException if fragment is not supported.
464      * @since 2.4
465      */
466     private static long getFragment(final Date date, final int fragment, final TimeUnit unit) {
467         validateDateNotNull(date);
468         final Calendar calendar = Calendar.getInstance();
469         calendar.setTime(date);
470         return getFragment(calendar, fragment, unit);
471     }
472 
473     /**
474      * Gets the number of days within the
475      * fragment. All datefields greater than the fragment will be ignored.
476      *
477      * <p>Asking the days of any date will only return the number of days
478      * of the current month (resulting in a number between 1 and 31). This
479      * method will retrieve the number of days for any fragment.
480      * For example, if you want to calculate the number of days past this year,
481      * your fragment is Calendar.YEAR. The result will be all days of the
482      * past month(s).</p>
483      *
484      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
485      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
486      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
487      * A fragment less than or equal to a DAY field will return 0.</p>
488      *
489      * <ul>
490      *  <li>January 28, 2008 with Calendar.MONTH as fragment will return 28
491      *   (equivalent to calendar.get(Calendar.DAY_OF_MONTH))</li>
492      *  <li>February 28, 2008 with Calendar.MONTH as fragment will return 28
493      *   (equivalent to calendar.get(Calendar.DAY_OF_MONTH))</li>
494      *  <li>January 28, 2008 with Calendar.YEAR as fragment will return 28
495      *   (equivalent to calendar.get(Calendar.DAY_OF_YEAR))</li>
496      *  <li>February 28, 2008 with Calendar.YEAR as fragment will return 59
497      *   (equivalent to calendar.get(Calendar.DAY_OF_YEAR))</li>
498      *  <li>January 28, 2008 with Calendar.MILLISECOND as fragment will return 0
499      *   (a millisecond cannot be split in days)</li>
500      * </ul>
501      *
502      * @param calendar the calendar to work with, not null.
503      * @param fragment the {@link Calendar} field part of calendar to calculate.
504      * @return number of days within the fragment of date.
505      * @throws NullPointerException if the date is {@code null} or
506      * fragment is not supported.
507      * @since 2.4
508      */
509     public static long getFragmentInDays(final Calendar calendar, final int fragment) {
510         return getFragment(calendar, fragment, TimeUnit.DAYS);
511     }
512 
513     /**
514      * Gets the number of days within the
515      * fragment. All date fields greater than the fragment will be ignored.
516      *
517      * <p>Asking the days of any date will only return the number of days
518      * of the current month (resulting in a number between 1 and 31). This
519      * method will retrieve the number of days for any fragment.
520      * For example, if you want to calculate the number of days past this year,
521      * your fragment is Calendar.YEAR. The result will be all days of the
522      * past month(s).</p>
523      *
524      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
525      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
526      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
527      * A fragment less than or equal to a DAY field will return 0.</p>
528      *
529      * <ul>
530      *  <li>January 28, 2008 with Calendar.MONTH as fragment will return 28
531      *   (equivalent to deprecated date.getDay())</li>
532      *  <li>February 28, 2008 with Calendar.MONTH as fragment will return 28
533      *   (equivalent to deprecated date.getDay())</li>
534      *  <li>January 28, 2008 with Calendar.YEAR as fragment will return 28</li>
535      *  <li>February 28, 2008 with Calendar.YEAR as fragment will return 59</li>
536      *  <li>January 28, 2008 with Calendar.MILLISECOND as fragment will return 0
537      *   (a millisecond cannot be split in days)</li>
538      * </ul>
539      *
540      * @param date the date to work with, not null.
541      * @param fragment the {@link Calendar} field part of date to calculate.
542      * @return number of days  within the fragment of date.
543      * @throws NullPointerException if the date is {@code null}.
544      * @throws IllegalArgumentException if the fragment is not supported.
545      * @since 2.4
546      */
547     public static long getFragmentInDays(final Date date, final int fragment) {
548         return getFragment(date, fragment, TimeUnit.DAYS);
549     }
550 
551     /**
552      * Gets the number of hours within the
553      * fragment. All date fields greater than the fragment will be ignored.
554      *
555      * <p>Asking the hours of any date will only return the number of hours
556      * of the current day (resulting in a number between 0 and 23). This
557      * method will retrieve the number of hours for any fragment.
558      * For example, if you want to calculate the number of hours past this month,
559      * your fragment is Calendar.MONTH. The result will be all hours of the
560      * past day(s).</p>
561      *
562      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
563      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
564      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
565      * A fragment less than or equal to a HOUR field will return 0.</p>
566      *
567      * <ul>
568      *  <li>January 1, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 7
569      *   (equivalent to calendar.get(Calendar.HOUR_OF_DAY))</li>
570      *  <li>January 6, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 7
571      *   (equivalent to calendar.get(Calendar.HOUR_OF_DAY))</li>
572      *  <li>January 1, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 7</li>
573      *  <li>January 6, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 127 (5*24 + 7)</li>
574      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
575      *   (a millisecond cannot be split in hours)</li>
576      * </ul>
577      *
578      * @param calendar the calendar to work with, not null.
579      * @param fragment the {@link Calendar} field part of calendar to calculate.
580      * @return number of hours within the fragment of date.
581      * @throws NullPointerException if the date is {@code null} or
582      * fragment is not supported.
583      * @since 2.4
584      */
585     public static long getFragmentInHours(final Calendar calendar, final int fragment) {
586         return getFragment(calendar, fragment, TimeUnit.HOURS);
587     }
588 
589     /**
590      * Gets the number of hours within the
591      * fragment. All date fields greater than the fragment will be ignored.
592      *
593      * <p>Asking the hours of any date will only return the number of hours
594      * of the current day (resulting in a number between 0 and 23). This
595      * method will retrieve the number of hours for any fragment.
596      * For example, if you want to calculate the number of hours past this month,
597      * your fragment is Calendar.MONTH. The result will be all hours of the
598      * past day(s).</p>
599      *
600      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
601      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
602      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
603      * A fragment less than or equal to a HOUR field will return 0.</p>
604      *
605      * <ul>
606      *  <li>January 1, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 7
607      *   (equivalent to deprecated date.getHours())</li>
608      *  <li>January 6, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 7
609      *   (equivalent to deprecated date.getHours())</li>
610      *  <li>January 1, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 7</li>
611      *  <li>January 6, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 127 (5*24 + 7)</li>
612      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
613      *   (a millisecond cannot be split in hours)</li>
614      * </ul>
615      *
616      * @param date the date to work with, not null.
617      * @param fragment the {@link Calendar} field part of date to calculate.
618      * @return number of hours within the fragment of date.
619      * @throws NullPointerException if the date is {@code null}.
620      * @throws IllegalArgumentException if the fragment is not supported.
621      * @since 2.4
622      */
623     public static long getFragmentInHours(final Date date, final int fragment) {
624         return getFragment(date, fragment, TimeUnit.HOURS);
625     }
626 
627     /**
628      * Gets the number of milliseconds within the
629      * fragment. All date fields greater than the fragment will be ignored.
630      *
631      * <p>Asking the milliseconds of any date will only return the number of milliseconds
632      * of the current second (resulting in a number between 0 and 999). This
633      * method will retrieve the number of milliseconds for any fragment.
634      * For example, if you want to calculate the number of seconds past today,
635      * your fragment is Calendar.DATE or Calendar.DAY_OF_YEAR. The result will
636      * be all seconds of the past hour(s), minutes(s) and second(s).</p>
637      *
638      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
639      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
640      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
641      * A fragment less than or equal to a MILLISECOND field will return 0.</p>
642      *
643      * <ul>
644      *  <li>January 1, 2008 7:15:10.538 with Calendar.SECOND as fragment will return 538
645      *   (equivalent to calendar.get(Calendar.MILLISECOND))</li>
646      *  <li>January 6, 2008 7:15:10.538 with Calendar.SECOND as fragment will return 538
647      *   (equivalent to calendar.get(Calendar.MILLISECOND))</li>
648      *  <li>January 6, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10538
649      *   (10*1000 + 538)</li>
650      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
651      *   (a millisecond cannot be split in milliseconds)</li>
652      * </ul>
653      *
654      * @param calendar the calendar to work with, not null.
655      * @param fragment the {@link Calendar} field part of calendar to calculate.
656      * @return number of milliseconds within the fragment of date.
657      * @throws NullPointerException if the date is {@code null} or
658      * fragment is not supported.
659      * @since 2.4
660      */
661   public static long getFragmentInMilliseconds(final Calendar calendar, final int fragment) {
662     return getFragment(calendar, fragment, TimeUnit.MILLISECONDS);
663   }
664 
665     /**
666      * Gets the number of milliseconds within the
667      * fragment. All date fields greater than the fragment will be ignored.
668      *
669      * <p>Asking the milliseconds of any date will only return the number of milliseconds
670      * of the current second (resulting in a number between 0 and 999). This
671      * method will retrieve the number of milliseconds for any fragment.
672      * For example, if you want to calculate the number of milliseconds past today,
673      * your fragment is Calendar.DATE or Calendar.DAY_OF_YEAR. The result will
674      * be all milliseconds of the past hour(s), minutes(s) and second(s).</p>
675      *
676      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
677      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
678      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
679      * A fragment less than or equal to a SECOND field will return 0.</p>
680      *
681      * <ul>
682      *  <li>January 1, 2008 7:15:10.538 with Calendar.SECOND as fragment will return 538</li>
683      *  <li>January 6, 2008 7:15:10.538 with Calendar.SECOND as fragment will return 538</li>
684      *  <li>January 6, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10538 (10*1000 + 538)</li>
685      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
686      *   (a millisecond cannot be split in milliseconds)</li>
687      * </ul>
688      *
689      * @param date the date to work with, not null.
690      * @param fragment the {@link Calendar} field part of date to calculate.
691      * @return number of milliseconds within the fragment of date.
692      * @throws NullPointerException if the date is {@code null}.
693      * @throws IllegalArgumentException if the fragment is not supported.
694      * @since 2.4
695      */
696     public static long getFragmentInMilliseconds(final Date date, final int fragment) {
697         return getFragment(date, fragment, TimeUnit.MILLISECONDS);
698     }
699 
700     /**
701      * Gets the number of minutes within the
702      * fragment. All date fields greater than the fragment will be ignored.
703      *
704      * <p>Asking the minutes of any date will only return the number of minutes
705      * of the current hour (resulting in a number between 0 and 59). This
706      * method will retrieve the number of minutes for any fragment.
707      * For example, if you want to calculate the number of minutes past this month,
708      * your fragment is Calendar.MONTH. The result will be all minutes of the
709      * past day(s) and hour(s).</p>
710      *
711      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
712      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
713      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
714      * A fragment less than or equal to a MINUTE field will return 0.</p>
715      *
716      * <ul>
717      *  <li>January 1, 2008 7:15:10.538 with Calendar.HOUR_OF_DAY as fragment will return 15
718      *   (equivalent to calendar.get(Calendar.MINUTES))</li>
719      *  <li>January 6, 2008 7:15:10.538 with Calendar.HOUR_OF_DAY as fragment will return 15
720      *   (equivalent to calendar.get(Calendar.MINUTES))</li>
721      *  <li>January 1, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 15</li>
722      *  <li>January 6, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 435 (7*60 + 15)</li>
723      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
724      *   (a millisecond cannot be split in minutes)</li>
725      * </ul>
726      *
727      * @param calendar the calendar to work with, not null.
728      * @param fragment the {@link Calendar} field part of calendar to calculate.
729      * @return number of minutes within the fragment of date.
730      * @throws NullPointerException if the date is {@code null} or
731      * fragment is not supported.
732      * @since 2.4
733      */
734     public static long getFragmentInMinutes(final Calendar calendar, final int fragment) {
735         return getFragment(calendar, fragment, TimeUnit.MINUTES);
736     }
737 
738     /**
739      * Gets the number of minutes within the
740      * fragment. All date fields greater than the fragment will be ignored.
741      *
742      * <p>Asking the minutes of any date will only return the number of minutes
743      * of the current hour (resulting in a number between 0 and 59). This
744      * method will retrieve the number of minutes for any fragment.
745      * For example, if you want to calculate the number of minutes past this month,
746      * your fragment is Calendar.MONTH. The result will be all minutes of the
747      * past day(s) and hour(s).</p>
748      *
749      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
750      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
751      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
752      * A fragment less than or equal to a MINUTE field will return 0.</p>
753      *
754      * <ul>
755      *  <li>January 1, 2008 7:15:10.538 with Calendar.HOUR_OF_DAY as fragment will return 15
756      *   (equivalent to deprecated date.getMinutes())</li>
757      *  <li>January 6, 2008 7:15:10.538 with Calendar.HOUR_OF_DAY as fragment will return 15
758      *   (equivalent to deprecated date.getMinutes())</li>
759      *  <li>January 1, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 15</li>
760      *  <li>January 6, 2008 7:15:10.538 with Calendar.MONTH as fragment will return 435 (7*60 + 15)</li>
761      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
762      *   (a millisecond cannot be split in minutes)</li>
763      * </ul>
764      *
765      * @param date the date to work with, not null.
766      * @param fragment the {@link Calendar} field part of date to calculate.
767      * @return number of minutes within the fragment of date.
768      * @throws NullPointerException if the date is {@code null}.
769      * @throws IllegalArgumentException if the fragment is not supported.
770      * @since 2.4
771      */
772     public static long getFragmentInMinutes(final Date date, final int fragment) {
773         return getFragment(date, fragment, TimeUnit.MINUTES);
774     }
775 
776     /**
777      * Gets the number of seconds within the
778      * fragment. All date fields greater than the fragment will be ignored.
779      *
780      * <p>Asking the seconds of any date will only return the number of seconds
781      * of the current minute (resulting in a number between 0 and 59). This
782      * method will retrieve the number of seconds for any fragment.
783      * For example, if you want to calculate the number of seconds past today,
784      * your fragment is Calendar.DATE or Calendar.DAY_OF_YEAR. The result will
785      * be all seconds of the past hour(s) and minutes(s).</p>
786      *
787      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
788      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
789      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
790      * A fragment less than or equal to a SECOND field will return 0.</p>
791      *
792      * <ul>
793      *  <li>January 1, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10
794      *   (equivalent to calendar.get(Calendar.SECOND))</li>
795      *  <li>January 6, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10
796      *   (equivalent to calendar.get(Calendar.SECOND))</li>
797      *  <li>January 6, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 26110
798      *   (7*3600 + 15*60 + 10)</li>
799      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
800      *   (a millisecond cannot be split in seconds)</li>
801      * </ul>
802      *
803      * @param calendar the calendar to work with, not null.
804      * @param fragment the {@link Calendar} field part of calendar to calculate.
805      * @return number of seconds within the fragment of date.
806      * @throws NullPointerException if the date is {@code null} or
807      * fragment is not supported.
808      * @since 2.4
809      */
810     public static long getFragmentInSeconds(final Calendar calendar, final int fragment) {
811         return getFragment(calendar, fragment, TimeUnit.SECONDS);
812     }
813 
814     /**
815      * Gets the number of seconds within the
816      * fragment. All date fields greater than the fragment will be ignored.
817      *
818      * <p>Asking the seconds of any date will only return the number of seconds
819      * of the current minute (resulting in a number between 0 and 59). This
820      * method will retrieve the number of seconds for any fragment.
821      * For example, if you want to calculate the number of seconds past today,
822      * your fragment is Calendar.DATE or Calendar.DAY_OF_YEAR. The result will
823      * be all seconds of the past hour(s) and minutes(s).</p>
824      *
825      * <p>Valid fragments are: Calendar.YEAR, Calendar.MONTH, both
826      * Calendar.DAY_OF_YEAR and Calendar.DATE, Calendar.HOUR_OF_DAY,
827      * Calendar.MINUTE, Calendar.SECOND and Calendar.MILLISECOND
828      * A fragment less than or equal to a SECOND field will return 0.</p>
829      *
830      * <ul>
831      *  <li>January 1, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10
832      *   (equivalent to deprecated date.getSeconds())</li>
833      *  <li>January 6, 2008 7:15:10.538 with Calendar.MINUTE as fragment will return 10
834      *   (equivalent to deprecated date.getSeconds())</li>
835      *  <li>January 6, 2008 7:15:10.538 with Calendar.DAY_OF_YEAR as fragment will return 26110
836      *   (7*3600 + 15*60 + 10)</li>
837      *  <li>January 16, 2008 7:15:10.538 with Calendar.MILLISECOND as fragment will return 0
838      *   (a millisecond cannot be split in seconds)</li>
839      * </ul>
840      *
841      * @param date the date to work with, not null.
842      * @param fragment the {@link Calendar} field part of date to calculate.
843      * @return number of seconds within the fragment of date.
844      * @throws NullPointerException if the date is {@code null}.
845      * @throws IllegalArgumentException if the fragment is not supported.
846      * @since 2.4
847      */
848     public static long getFragmentInSeconds(final Date date, final int fragment) {
849         return getFragment(date, fragment, TimeUnit.SECONDS);
850     }
851 
852     /**
853      * Tests whether two calendar objects are on the same day ignoring time.
854      *
855      * <p>28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true.
856      * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.
857      * </p>
858      *
859      * @param cal1  the first calendar, not altered, not null.
860      * @param cal2  the second calendar, not altered, not null.
861      * @return true if they represent the same day.
862      * @throws NullPointerException if either calendar is {@code null}.
863      * @since 2.1
864      */
865     public static boolean isSameDay(final Calendar cal1, final Calendar cal2) {
866         Objects.requireNonNull(cal1, "cal1");
867         Objects.requireNonNull(cal2, "cal2");
868         return cal1.get(Calendar.ERA) == cal2.get(Calendar.ERA) &&
869                 cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) &&
870                 cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR);
871     }
872 
873     /**
874      * Tests whether two date objects are on the same day ignoring time.
875      *
876      * <p>28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true.
877      * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.
878      * </p>
879      *
880      * @param date1  the first date, not altered, not null.
881      * @param date2  the second date, not altered, not null.
882      * @return true if they represent the same day.
883      * @throws NullPointerException if either date is {@code null}.
884      * @since 2.1
885      */
886     public static boolean isSameDay(final Date date1, final Date date2) {
887         return isSameDay(toCalendar(date1), toCalendar(date2));
888     }
889 
890     /**
891      * Tests whether two calendar objects represent the same instant in time.
892      *
893      * <p>This method compares the long millisecond time of the two objects.</p>
894      *
895      * @param cal1  the first calendar, not altered, not null.
896      * @param cal2  the second calendar, not altered, not null.
897      * @return true if they represent the same millisecond instant.
898      * @throws NullPointerException if either date is {@code null}.
899      * @since 2.1
900      */
901     public static boolean isSameInstant(final Calendar cal1, final Calendar cal2) {
902         Objects.requireNonNull(cal1, "cal1");
903         Objects.requireNonNull(cal2, "cal2");
904         return cal1.getTime().getTime() == cal2.getTime().getTime();
905     }
906 
907     /**
908      * Tests whether two date objects represent the same instant in time.
909      *
910      * <p>This method compares the long millisecond time of the two objects.</p>
911      *
912      * @param date1  the first date, not altered, not null.
913      * @param date2  the second date, not altered, not null.
914      * @return true if they represent the same millisecond instant.
915      * @throws NullPointerException if either date is {@code null}.
916      * @since 2.1
917      */
918     public static boolean isSameInstant(final Date date1, final Date date2) {
919         Objects.requireNonNull(date1, "date1");
920         Objects.requireNonNull(date2, "date2");
921         return date1.getTime() == date2.getTime();
922     }
923 
924     /**
925      * Tests whether two calendar objects represent the same local time.
926      *
927      * <p>This method compares the values of the fields of the two objects.
928      * In addition, both calendars must be the same of the same type.</p>
929      *
930      * @param cal1  the first calendar, not altered, not null.
931      * @param cal2  the second calendar, not altered, not null.
932      * @return true if they represent the same millisecond instant.
933      * @throws NullPointerException if either date is {@code null}.
934      * @since 2.1
935      */
936     public static boolean isSameLocalTime(final Calendar cal1, final Calendar cal2) {
937         Objects.requireNonNull(cal1, "cal1");
938         Objects.requireNonNull(cal2, "cal2");
939         return cal1.get(Calendar.MILLISECOND) == cal2.get(Calendar.MILLISECOND) &&
940                 cal1.get(Calendar.SECOND) == cal2.get(Calendar.SECOND) &&
941                 cal1.get(Calendar.MINUTE) == cal2.get(Calendar.MINUTE) &&
942                 cal1.get(Calendar.HOUR_OF_DAY) == cal2.get(Calendar.HOUR_OF_DAY) &&
943                 cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR) &&
944                 cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) &&
945                 cal1.get(Calendar.ERA) == cal2.get(Calendar.ERA) &&
946                 cal1.getClass() == cal2.getClass();
947     }
948 
949     /**
950      * Constructs an {@link Iterator} over each day in a date
951      * range defined by a focus date and range style.
952      *
953      * <p>For instance, passing Thursday, July 4, 2002 and a
954      * {@code RANGE_MONTH_SUNDAY} will return an {@link Iterator}
955      * that starts with Sunday, June 30, 2002 and ends with Saturday, August 3,
956      * 2002, returning a Calendar instance for each intermediate day.</p>
957      *
958      * <p>This method provides an iterator that returns Calendar objects.
959      * The days are progressed using {@link Calendar#add(int, int)}.</p>
960      *
961      * @param calendar  the date to work with, not null.
962      * @param rangeStyle  the style constant to use. Must be one of
963      * {@link DateUtils#RANGE_MONTH_SUNDAY},
964      * {@link DateUtils#RANGE_MONTH_MONDAY},
965      * {@link DateUtils#RANGE_WEEK_SUNDAY},
966      * {@link DateUtils#RANGE_WEEK_MONDAY},
967      * {@link DateUtils#RANGE_WEEK_RELATIVE},
968      * {@link DateUtils#RANGE_WEEK_CENTER}.
969      * @return the date iterator, not null.
970      * @throws NullPointerException if calendar is {@code null}.
971      * @throws IllegalArgumentException if the rangeStyle is invalid.
972      */
973     public static Iterator<Calendar> iterator(final Calendar calendar, final int rangeStyle) {
974         Objects.requireNonNull(calendar, "calendar");
975         final Calendar start;
976         final Calendar end;
977         int startCutoff = Calendar.SUNDAY;
978         int endCutoff = Calendar.SATURDAY;
979         switch (rangeStyle) {
980             case RANGE_MONTH_SUNDAY:
981             case RANGE_MONTH_MONDAY:
982                 //Set start to the first of the month
983                 start = truncate(calendar, Calendar.MONTH);
984                 //Set end to the last of the month
985                 end = (Calendar) start.clone();
986                 end.add(Calendar.MONTH, 1);
987                 end.add(Calendar.DATE, -1);
988                 //Loop start back to the previous sunday or monday
989                 if (rangeStyle == RANGE_MONTH_MONDAY) {
990                     startCutoff = Calendar.MONDAY;
991                     endCutoff = Calendar.SUNDAY;
992                 }
993                 break;
994             case RANGE_WEEK_SUNDAY:
995             case RANGE_WEEK_MONDAY:
996             case RANGE_WEEK_RELATIVE:
997             case RANGE_WEEK_CENTER:
998                 //Set start and end to the current date
999                 start = truncate(calendar, Calendar.DATE);
1000                 end = truncate(calendar, Calendar.DATE);
1001                 switch (rangeStyle) {
1002                     case RANGE_WEEK_SUNDAY:
1003                         //already set by default
1004                         break;
1005                     case RANGE_WEEK_MONDAY:
1006                         startCutoff = Calendar.MONDAY;
1007                         endCutoff = Calendar.SUNDAY;
1008                         break;
1009                     case RANGE_WEEK_RELATIVE:
1010                         startCutoff = calendar.get(Calendar.DAY_OF_WEEK);
1011                         endCutoff = startCutoff - 1;
1012                         break;
1013                     case RANGE_WEEK_CENTER:
1014                         startCutoff = calendar.get(Calendar.DAY_OF_WEEK) - 3;
1015                         endCutoff = calendar.get(Calendar.DAY_OF_WEEK) + 3;
1016                         break;
1017                     default:
1018                         break;
1019                 }
1020                 break;
1021             default:
1022                 throw new IllegalArgumentException("The range style " + rangeStyle + " is not valid.");
1023         }
1024         if (startCutoff < Calendar.SUNDAY) {
1025             startCutoff += 7;
1026         }
1027         if (startCutoff > Calendar.SATURDAY) {
1028             startCutoff -= 7;
1029         }
1030         if (endCutoff < Calendar.SUNDAY) {
1031             endCutoff += 7;
1032         }
1033         if (endCutoff > Calendar.SATURDAY) {
1034             endCutoff -= 7;
1035         }
1036         while (start.get(Calendar.DAY_OF_WEEK) != startCutoff) {
1037             start.add(Calendar.DATE, -1);
1038         }
1039         while (end.get(Calendar.DAY_OF_WEEK) != endCutoff) {
1040             end.add(Calendar.DATE, 1);
1041         }
1042         return new DateIterator(start, end);
1043     }
1044 
1045     /**
1046      * Constructs an {@link Iterator} over each day in a date
1047      * range defined by a focus date and range style.
1048      *
1049      * <p>For instance, passing Thursday, July 4, 2002 and a
1050      * {@code RANGE_MONTH_SUNDAY} will return an {@link Iterator}
1051      * that starts with Sunday, June 30, 2002 and ends with Saturday, August 3,
1052      * 2002, returning a Calendar instance for each intermediate day.</p>
1053      *
1054      * <p>This method provides an iterator that returns Calendar objects.
1055      * The days are progressed using {@link Calendar#add(int, int)}.</p>
1056      *
1057      * @param focus  the date to work with, not null.
1058      * @param rangeStyle  the style constant to use. Must be one of
1059      * {@link DateUtils#RANGE_MONTH_SUNDAY},
1060      * {@link DateUtils#RANGE_MONTH_MONDAY},
1061      * {@link DateUtils#RANGE_WEEK_SUNDAY},
1062      * {@link DateUtils#RANGE_WEEK_MONDAY},
1063      * {@link DateUtils#RANGE_WEEK_RELATIVE},
1064      * {@link DateUtils#RANGE_WEEK_CENTER}.
1065      * @return the date iterator, not null, not null.
1066      * @throws NullPointerException if the date is {@code null}.
1067      * @throws IllegalArgumentException if the rangeStyle is invalid.
1068      */
1069     public static Iterator<Calendar> iterator(final Date focus, final int rangeStyle) {
1070         return iterator(toCalendar(focus), rangeStyle);
1071     }
1072 
1073     /**
1074      * Constructs an {@link Iterator} over each day in a date
1075      * range defined by a focus date and range style.
1076      *
1077      * <p>For instance, passing Thursday, July 4, 2002 and a
1078      * {@code RANGE_MONTH_SUNDAY} will return an {@link Iterator}
1079      * that starts with Sunday, June 30, 2002 and ends with Saturday, August 3,
1080      * 2002, returning a Calendar instance for each intermediate day.</p>
1081      *
1082      * @param calendar  the date to work with, either {@link Date} or {@link Calendar}, not null.
1083      * @param rangeStyle  the style constant to use. Must be one of the range
1084      * styles listed for the {@link #iterator(Calendar, int)} method.
1085      * @return the date iterator, not null.
1086      * @throws NullPointerException if the date is {@code null}.
1087      * @throws ClassCastException if the object type is not a {@link Date} or {@link Calendar}.
1088      */
1089     public static Iterator<?> iterator(final Object calendar, final int rangeStyle) {
1090         Objects.requireNonNull(calendar, "calendar");
1091         if (calendar instanceof Date) {
1092             return iterator((Date) calendar, rangeStyle);
1093         }
1094         if (calendar instanceof Calendar) {
1095             return iterator((Calendar) calendar, rangeStyle);
1096         }
1097         throw new ClassCastException("Could not iterate based on " + calendar);
1098     }
1099 
1100     /**
1101      * Internal calculation method.
1102      *
1103      * @param val  the calendar, not null.
1104      * @param field  the field constant.
1105      * @param modType  type to truncate, round or ceiling.
1106      * @return the given calendar.
1107      * @throws ArithmeticException if the year is over 280 million.
1108      */
1109     private static Calendar modify(final Calendar val, final int field, final ModifyType modType) {
1110         if (val.get(Calendar.YEAR) > 280000000) {
1111             throw new ArithmeticException("Calendar value too large for accurate calculations");
1112         }
1113         if (field == Calendar.MILLISECOND) {
1114             return val;
1115         }
1116         final long originalMillis = val.getTimeInMillis();
1117         // Fix for LANG-59 START
1118         // see https://issues.apache.org/jira/browse/LANG-59
1119         //
1120         // Manually truncate milliseconds, seconds and minutes, rather than using
1121         // Calendar methods.
1122         final Date date = val.getTime();
1123         long time = date.getTime();
1124         boolean done = false;
1125         // truncate milliseconds
1126         final int millisecs = val.get(Calendar.MILLISECOND);
1127         if (ModifyType.TRUNCATE == modType || millisecs < 500) {
1128             time -= millisecs;
1129         }
1130         if (field == Calendar.SECOND) {
1131             done = true;
1132         }
1133         // truncate seconds
1134         final int seconds = val.get(Calendar.SECOND);
1135         if (!done && (ModifyType.TRUNCATE == modType || seconds < 30)) {
1136             time = time - seconds * MILLIS_PER_SECOND;
1137         }
1138         if (field == Calendar.MINUTE) {
1139             done = true;
1140         }
1141         // truncate minutes
1142         final int minutes = val.get(Calendar.MINUTE);
1143         if (!done && (ModifyType.TRUNCATE == modType || minutes < 30)) {
1144             time = time - minutes * MILLIS_PER_MINUTE;
1145         }
1146         // reset time
1147         if (date.getTime() != time) {
1148             date.setTime(time);
1149             val.setTime(date);
1150         }
1151         // Fix for LANG-59 END
1152         boolean roundUp = false;
1153         for (final int[] aField : fields) {
1154             for (final int element : aField) {
1155                 if (element == field) {
1156                     // This is our field... we stop looping
1157                     if (modType == ModifyType.CEILING && originalMillis != val.getTimeInMillis() || modType == ModifyType.ROUND && roundUp) {
1158                         if (field == SEMI_MONTH) {
1159                             // This is a special case that's hard to generalize
1160                             // If the date is 1, we round up to 16, otherwise
1161                             // we subtract 15 days and add 1 month
1162                             if (val.get(Calendar.DATE) == 1) {
1163                                 val.add(Calendar.DATE, 15);
1164                             } else {
1165                                 val.add(Calendar.DATE, -15);
1166                                 val.add(Calendar.MONTH, 1);
1167                             }
1168                             // Fix for LANG-440 START
1169                         } else if (field == Calendar.AM_PM) {
1170                             // This is a special case
1171                             // If the time is 0, we round up to 12, otherwise
1172                             // we subtract 12 hours and add 1 day
1173                             if (val.get(Calendar.HOUR_OF_DAY) == 0) {
1174                                 val.add(Calendar.HOUR_OF_DAY, 12);
1175                             } else {
1176                                 val.add(Calendar.HOUR_OF_DAY, -12);
1177                                 val.add(Calendar.DATE, 1);
1178                             }
1179                             // Fix for LANG-440 END
1180                         } else {
1181                             // We need at add one to this field since the
1182                             // last number causes us to round up
1183                             val.add(aField[0], 1);
1184                         }
1185                     }
1186                     return val;
1187                 }
1188             }
1189             // We have various fields that are not easy roundings
1190             int offset = 0;
1191             boolean offsetSet = false;
1192             // These are special types of fields that require different rounding rules
1193             switch (field) {
1194             case SEMI_MONTH:
1195                 if (aField[0] == Calendar.DATE) {
1196                     // If we're going to drop the DATE field's value,
1197                     // we want to do this our own way.
1198                     // We need to subtract 1 since the date has a minimum of 1
1199                     offset = val.get(Calendar.DATE) - 1;
1200                     // If we're above 15 days adjustment, that means we're in the
1201                     // bottom half of the month and should stay accordingly.
1202                     if (offset >= 15) {
1203                         offset -= 15;
1204                     }
1205                     // Record whether we're in the top or bottom half of that range
1206                     roundUp = offset > 7;
1207                     offsetSet = true;
1208                 }
1209                 break;
1210             case Calendar.AM_PM:
1211                 if (aField[0] == Calendar.HOUR_OF_DAY) {
1212                     // If we're going to drop the HOUR field's value,
1213                     // we want to do this our own way.
1214                     offset = val.get(Calendar.HOUR_OF_DAY);
1215                     if (offset >= 12) {
1216                         offset -= 12;
1217                     }
1218                     roundUp = offset >= 6;
1219                     offsetSet = true;
1220                 }
1221                 break;
1222             default:
1223                 break;
1224             }
1225             if (!offsetSet) {
1226                 final int min = val.getActualMinimum(aField[0]);
1227                 final int max = val.getActualMaximum(aField[0]);
1228                 // Calculate the offset from the minimum allowed value
1229                 offset = val.get(aField[0]) - min;
1230                 // Set roundUp if this is more than halfway between the minimum and maximum
1231                 roundUp = offset > (max - min) / 2;
1232             }
1233             // We need to remove this field
1234             if (offset != 0) {
1235                 val.set(aField[0], val.get(aField[0]) - offset);
1236             }
1237         }
1238         throw new IllegalArgumentException("The field " + field + " is not supported");
1239     }
1240 
1241     /**
1242      * Parses a string representing a date by trying a variety of different parsers,
1243      * using the default date format symbols for the given locale.
1244      *
1245      * <p>The parse will try each parse pattern in turn.
1246      * A parse is only deemed successful if it parses the whole of the input string.
1247      * If no parse patterns match, a ParseException is thrown.</p>
1248      * The parser will be lenient toward the parsed date.
1249      *
1250      * @param str  the date to parse, not null.
1251      * @param locale the locale whose date format symbols should be used. If {@code null},
1252      * the system locale is used (as per {@link #parseDate(String, String...)}).
1253      * @param parsePatterns  the date format patterns to use, see SimpleDateFormat, not null.
1254      * @return the parsed date.
1255      * @throws NullPointerException if the date string or pattern array is null.
1256      * @throws ParseException if none of the date patterns were suitable (or there were none).
1257      * @since 3.2
1258      */
1259     public static Date parseDate(final String str, final Locale locale, final String... parsePatterns) throws ParseException {
1260         return parseDateWithLeniency(str, locale, parsePatterns, true);
1261     }
1262 
1263     /**
1264      * Parses a string representing a date by trying a variety of different parsers.
1265      *
1266      * <p>The parse will try each parse pattern in turn.
1267      * A parse is only deemed successful if it parses the whole of the input string.
1268      * If no parse patterns match, a ParseException is thrown.</p>
1269      * The parser will be lenient toward the parsed date.
1270      *
1271      * @param str  the date to parse, not null.
1272      * @param parsePatterns  the date format patterns to use, see SimpleDateFormat, not null.
1273      * @return the parsed date.
1274      * @throws NullPointerException if the date string or pattern array is null.
1275      * @throws ParseException if none of the date patterns were suitable (or there were none).
1276      */
1277     public static Date parseDate(final String str, final String... parsePatterns) throws ParseException {
1278         return parseDate(str, null, parsePatterns);
1279     }
1280 
1281     /**
1282      * Parses a string representing a date by trying a variety of different parsers,
1283      * using the default date format symbols for the given locale.
1284      *
1285      * <p>The parse will try each parse pattern in turn.
1286      * A parse is only deemed successful if it parses the whole of the input string.
1287      * If no parse patterns match, a ParseException is thrown.</p>
1288      * The parser parses strictly - it does not allow for dates such as "February 942, 1996".
1289      *
1290      * @param str  the date to parse, not null.
1291      * @param locale the locale whose date format symbols should be used. If {@code null},
1292      * the system locale is used (as per {@link #parseDateStrictly(String, String...)}).
1293      * @param parsePatterns  the date format patterns to use, see SimpleDateFormat, not null.
1294      * @return the parsed date.
1295      * @throws NullPointerException if the date string or pattern array is null.
1296      * @throws ParseException if none of the date patterns were suitable.
1297      * @since 3.2
1298      */
1299     public static Date parseDateStrictly(final String str, final Locale locale, final String... parsePatterns) throws ParseException {
1300         return parseDateWithLeniency(str, locale, parsePatterns, false);
1301     }
1302 
1303     /**
1304      * Parses a string representing a date by trying a variety of different parsers.
1305      *
1306      * <p>The parse will try each parse pattern in turn.
1307      * A parse is only deemed successful if it parses the whole of the input string.
1308      * If no parse patterns match, a ParseException is thrown.</p>
1309      * The parser parses strictly - it does not allow for dates such as "February 942, 1996".
1310      *
1311      * @param str  the date to parse, not null.
1312      * @param parsePatterns  the date format patterns to use, see SimpleDateFormat, not null.
1313      * @return the parsed date.
1314      * @throws NullPointerException if the date string or pattern array is null.
1315      * @throws ParseException if none of the date patterns were suitable.
1316      * @since 2.5
1317      */
1318     public static Date parseDateStrictly(final String str, final String... parsePatterns) throws ParseException {
1319         return parseDateStrictly(str, null, parsePatterns);
1320     }
1321 
1322     /**
1323      * Parses a string representing a date by trying a variety of different parsers.
1324      *
1325      * <p>The parse will try each parse pattern in turn.
1326      * A parse is only deemed successful if it parses the whole of the input string.
1327      * If no parse patterns match, a ParseException is thrown.</p>
1328      *
1329      * @param dateStr  the date to parse, not null.
1330      * @param locale the locale to use when interpreting the pattern, can be null in which
1331      * case the default system locale is used.
1332      * @param parsePatterns  the date format patterns to use, see SimpleDateFormat, not null.
1333      * @param lenient Specify whether or not date/time parsing is to be lenient.
1334      * @return the parsed date.
1335      * @throws NullPointerException if the date string or pattern array is null.
1336      * @throws ParseException if none of the date patterns were suitable.
1337      * @see java.util.Calendar#isLenient()
1338      */
1339     private static Date parseDateWithLeniency(final String dateStr, final Locale locale, final String[] parsePatterns,
1340         final boolean lenient) throws ParseException {
1341         Objects.requireNonNull(dateStr, "str");
1342         Objects.requireNonNull(parsePatterns, "parsePatterns");
1343 
1344         final TimeZone tz = TimeZone.getDefault();
1345         final Locale lcl = LocaleUtils.toLocale(locale);
1346         final ParsePosition pos = new ParsePosition(0);
1347         final Calendar calendar = Calendar.getInstance(tz, lcl);
1348         calendar.setLenient(lenient);
1349 
1350         for (final String parsePattern : parsePatterns) {
1351             final FastDateParser fdp = new FastDateParser(parsePattern, tz, lcl);
1352             calendar.clear();
1353             try {
1354                 if (fdp.parse(dateStr, pos, calendar) && pos.getIndex() == dateStr.length()) {
1355                     return calendar.getTime();
1356                 }
1357             } catch (final IllegalArgumentException ignored) {
1358                 // leniency is preventing calendar from being set
1359             }
1360             pos.setIndex(0);
1361         }
1362         throw new ParseException("Unable to parse the date: " + dateStr, -1);
1363     }
1364 
1365     /**
1366      * Rounds a date, leaving the field specified as the most
1367      * significant field.
1368      *
1369      * <p>For example, if you had the date-time of 28 Mar 2002
1370      * 13:45:01.231, if this was passed with HOUR, it would return
1371      * 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it
1372      * would return 1 April 2002 0:00:00.000.</p>
1373      *
1374      * <p>For a date in a time zone that handles the change to daylight
1375      * saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows.
1376      * Suppose daylight saving time begins at 02:00 on March 30. Rounding a
1377      * date that crosses this time would produce the following values:
1378      * </p>
1379      * <ul>
1380      * <li>March 30, 2003 01:10 rounds to March 30, 2003 01:00</li>
1381      * <li>March 30, 2003 01:40 rounds to March 30, 2003 03:00</li>
1382      * <li>March 30, 2003 02:10 rounds to March 30, 2003 03:00</li>
1383      * <li>March 30, 2003 02:40 rounds to March 30, 2003 04:00</li>
1384      * </ul>
1385      *
1386      * @param calendar  the date to work with, not null.
1387      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1388      * @return the different rounded date, not null.
1389      * @throws NullPointerException if the date is {@code null}.
1390      * @throws ArithmeticException if the year is over 280 million.
1391      */
1392     public static Calendar round(final Calendar calendar, final int field) {
1393         Objects.requireNonNull(calendar, "calendar");
1394         return modify((Calendar) calendar.clone(), field, ModifyType.ROUND);
1395     }
1396 
1397     /**
1398      * Rounds a date, leaving the field specified as the most
1399      * significant field.
1400      *
1401      * <p>For example, if you had the date-time of 28 Mar 2002
1402      * 13:45:01.231, if this was passed with HOUR, it would return
1403      * 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it
1404      * would return 1 April 2002 0:00:00.000.</p>
1405      *
1406      * <p>For a date in a time zone that handles the change to daylight
1407      * saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows.
1408      * Suppose daylight saving time begins at 02:00 on March 30. Rounding a
1409      * date that crosses this time would produce the following values:
1410      * </p>
1411      * <ul>
1412      * <li>March 30, 2003 01:10 rounds to March 30, 2003 01:00</li>
1413      * <li>March 30, 2003 01:40 rounds to March 30, 2003 03:00</li>
1414      * <li>March 30, 2003 02:10 rounds to March 30, 2003 03:00</li>
1415      * <li>March 30, 2003 02:40 rounds to March 30, 2003 04:00</li>
1416      * </ul>
1417      *
1418      * @param date  the date to work with, not null.
1419      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1420      * @return the different rounded date, not null.
1421      * @throws NullPointerException if the date is null.
1422      * @throws ArithmeticException if the year is over 280 million.
1423      */
1424     public static Date round(final Date date, final int field) {
1425         return modify(toCalendar(date), field, ModifyType.ROUND).getTime();
1426     }
1427 
1428     /**
1429      * Rounds a date, leaving the field specified as the most
1430      * significant field.
1431      *
1432      * <p>For example, if you had the date-time of 28 Mar 2002
1433      * 13:45:01.231, if this was passed with HOUR, it would return
1434      * 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it
1435      * would return 1 April 2002 0:00:00.000.</p>
1436      *
1437      * <p>For a date in a time zone that handles the change to daylight
1438      * saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows.
1439      * Suppose daylight saving time begins at 02:00 on March 30. Rounding a
1440      * date that crosses this time would produce the following values:
1441      * </p>
1442      * <ul>
1443      * <li>March 30, 2003 01:10 rounds to March 30, 2003 01:00</li>
1444      * <li>March 30, 2003 01:40 rounds to March 30, 2003 03:00</li>
1445      * <li>March 30, 2003 02:10 rounds to March 30, 2003 03:00</li>
1446      * <li>March 30, 2003 02:40 rounds to March 30, 2003 04:00</li>
1447      * </ul>
1448      *
1449      * @param date  the date to work with, either {@link Date} or {@link Calendar}, not null.
1450      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1451      * @return the different rounded date, not null.
1452      * @throws NullPointerException if the date is {@code null}.
1453      * @throws ClassCastException if the object type is not a {@link Date} or {@link Calendar}.
1454      * @throws ArithmeticException if the year is over 280 million.
1455      */
1456     public static Date round(final Object date, final int field) {
1457         Objects.requireNonNull(date, "date");
1458         if (date instanceof Date) {
1459             return round((Date) date, field);
1460         }
1461         if (date instanceof Calendar) {
1462             return round((Calendar) date, field).getTime();
1463         }
1464         throw new ClassCastException("Could not round " + date);
1465     }
1466 
1467     /**
1468      * Sets the specified field to a date returning a new object.
1469      * This does not use a lenient calendar.
1470      * The original {@link Date} is unchanged.
1471      *
1472      * @param date  the date, not null.
1473      * @param calendarField  the {@link Calendar} field to set the amount to.
1474      * @param amount the amount to set.
1475      * @return a new {@link Date} set with the specified value.
1476      * @throws NullPointerException if the date is null.
1477      * @since 2.4
1478      */
1479     private static Date set(final Date date, final int calendarField, final int amount) {
1480         validateDateNotNull(date);
1481         // getInstance() returns a new object, so this method is thread safe.
1482         final Calendar c = Calendar.getInstance();
1483         c.setLenient(false);
1484         c.setTime(date);
1485         c.set(calendarField, amount);
1486         return c.getTime();
1487     }
1488 
1489     /**
1490      * Sets the day of month field to a date returning a new object.
1491      * The original {@link Date} is unchanged.
1492      *
1493      * @param date  the date, not null.
1494      * @param amount the amount to set.
1495      * @return a new {@link Date} set with the specified value.
1496      * @throws NullPointerException if the date is null.
1497      * @throws IllegalArgumentException if {@code amount} is not in the range
1498      *  {@code 1 <= amount <= 31}.
1499      * @since 2.4
1500      */
1501     public static Date setDays(final Date date, final int amount) {
1502         return set(date, Calendar.DAY_OF_MONTH, amount);
1503     }
1504 
1505     /**
1506      * Sets the hours field to a date returning a new object.  Hours range
1507      * from  0-23.
1508      * The original {@link Date} is unchanged.
1509      *
1510      * @param date  the date, not null.
1511      * @param amount the amount to set.
1512      * @return a new {@link Date} set with the specified value.
1513      * @throws NullPointerException if the date is null.
1514      * @throws IllegalArgumentException if {@code amount} is not in the range
1515      *  {@code 0 <= amount <= 23}.
1516      * @since 2.4
1517      */
1518     public static Date setHours(final Date date, final int amount) {
1519         return set(date, Calendar.HOUR_OF_DAY, amount);
1520     }
1521 
1522     /**
1523      * Sets the milliseconds field to a date returning a new object.
1524      * The original {@link Date} is unchanged.
1525      *
1526      * @param date  the date, not null.
1527      * @param amount the amount to set.
1528      * @return a new {@link Date} set with the specified value.
1529      * @throws NullPointerException if the date is null.
1530      * @throws IllegalArgumentException if {@code amount} is not in the range
1531      *  {@code 0 <= amount <= 999}.
1532      * @since 2.4
1533      */
1534     public static Date setMilliseconds(final Date date, final int amount) {
1535         return set(date, Calendar.MILLISECOND, amount);
1536     }
1537 
1538     /**
1539      * Sets the minute field to a date returning a new object.
1540      * The original {@link Date} is unchanged.
1541      *
1542      * @param date  the date, not null.
1543      * @param amount the amount to set.
1544      * @return a new {@link Date} set with the specified value.
1545      * @throws NullPointerException if the date is null.
1546      * @throws IllegalArgumentException if {@code amount} is not in the range
1547      *  {@code 0 <= amount <= 59}.
1548      * @since 2.4
1549      */
1550     public static Date setMinutes(final Date date, final int amount) {
1551         return set(date, Calendar.MINUTE, amount);
1552     }
1553 
1554     /**
1555      * Sets the months field to a date returning a new object.
1556      * The original {@link Date} is unchanged.
1557      *
1558      * @param date  the date, not null.
1559      * @param amount the amount to set.
1560      * @return a new {@link Date} set with the specified value.
1561      * @throws NullPointerException if the date is null.
1562      * @throws IllegalArgumentException if {@code amount} is not in the range
1563      *  {@code 0 <= amount <= 11}.
1564      * @since 2.4
1565      */
1566     public static Date setMonths(final Date date, final int amount) {
1567         return set(date, Calendar.MONTH, amount);
1568     }
1569 
1570     /**
1571      * Sets the seconds field to a date returning a new object.
1572      * The original {@link Date} is unchanged.
1573      *
1574      * @param date  the date, not null.
1575      * @param amount the amount to set.
1576      * @return a new {@link Date} set with the specified value.
1577      * @throws NullPointerException if the date is null.
1578      * @throws IllegalArgumentException if {@code amount} is not in the range
1579      *  {@code 0 <= amount <= 59}.
1580      * @since 2.4
1581      */
1582     public static Date setSeconds(final Date date, final int amount) {
1583         return set(date, Calendar.SECOND, amount);
1584     }
1585 
1586     /**
1587      * Sets the years field to a date returning a new object.
1588      * The original {@link Date} is unchanged.
1589      *
1590      * @param date  the date, not null.
1591      * @param amount the amount to set.
1592      * @return a new {@link Date} set with the specified value.
1593      * @throws NullPointerException if the date is null.
1594      * @since 2.4
1595      */
1596     public static Date setYears(final Date date, final int amount) {
1597         return set(date, Calendar.YEAR, amount);
1598     }
1599 
1600     /**
1601      * Converts a {@link Date} into a {@link Calendar}.
1602      *
1603      * @param date the date to convert to a Calendar.
1604      * @return the created Calendar.
1605      * @throws NullPointerException if null is passed in.
1606      * @since 3.0
1607      */
1608     public static Calendar toCalendar(final Date date) {
1609         final Calendar c = Calendar.getInstance();
1610         c.setTime(Objects.requireNonNull(date, "date"));
1611         return c;
1612     }
1613 
1614     /**
1615      * Converts a {@link Date} of a given {@link TimeZone} into a {@link Calendar}.
1616      *
1617      * @param date the date to convert to a Calendar.
1618      * @param tz the time zone of the {@code date}.
1619      * @return the created Calendar.
1620      * @throws NullPointerException if {@code date} or {@code tz} is null.
1621      */
1622     public static Calendar toCalendar(final Date date, final TimeZone tz) {
1623         final Calendar c = Calendar.getInstance(tz);
1624         c.setTime(Objects.requireNonNull(date, "date"));
1625         return c;
1626     }
1627 
1628     /**
1629      * Converts a {@link Date} to a {@link LocalDateTime}.
1630      *
1631      * @param date the Date to convert, not null.
1632      * @return a new LocalDateTime.
1633      * @since 3.19.0
1634      */
1635     public static LocalDateTime toLocalDateTime(final Date date) {
1636         return toLocalDateTime(date, TimeZone.getDefault());
1637     }
1638 
1639     /**
1640      * Converts a {@link Date} to a {@link LocalDateTime}.
1641      *
1642      * @param date     the Date to convert to a LocalDateTime, not null.
1643      * @param timeZone the time zone, null maps to the default time zone.
1644      * @return a new LocalDateTime.
1645      * @since 3.19.0
1646      */
1647     public static LocalDateTime toLocalDateTime(final Date date, final TimeZone timeZone) {
1648         return LocalDateTime.ofInstant(date.toInstant(), toZoneId(timeZone));
1649     }
1650 
1651     /**
1652      * Converts a {@link Date} to a {@link OffsetDateTime}.
1653      *
1654      * @param date the Date to convert, not null.
1655      * @return a new OffsetDateTime.
1656      * @since 3.19.0
1657      */
1658     public static OffsetDateTime toOffsetDateTime(final Date date) {
1659         return toOffsetDateTime(date, TimeZone.getDefault());
1660     }
1661 
1662     /**
1663      * Converts a {@link Date} to a {@link OffsetDateTime}.
1664      *
1665      * @param date     the Date to convert to a OffsetDateTime, not null.
1666      * @param timeZone the time zone, null maps to the default time zone.
1667      * @return a new OffsetDateTime.
1668      * @since 3.19.0
1669      */
1670     public static OffsetDateTime toOffsetDateTime(final Date date, final TimeZone timeZone) {
1671         return OffsetDateTime.ofInstant(date.toInstant(), toZoneId(timeZone));
1672     }
1673 
1674     /**
1675      * Converts a {@link Date} to a {@link ZonedDateTime}.
1676      *
1677      * @param date the Date to convert, not null.
1678      * @return a new ZonedDateTime.
1679      * @since 3.19.0
1680      */
1681     public static ZonedDateTime toZonedDateTime(final Date date) {
1682         return toZonedDateTime(date, TimeZone.getDefault());
1683     }
1684 
1685     /**
1686      * Converts a {@link Date} to a {@link ZonedDateTime}.
1687      *
1688      * @param date     the Date to convert to a ZonedDateTime, not null.
1689      * @param timeZone the time zone, null maps to the default time zone.
1690      * @return a new ZonedDateTime.
1691      * @since 3.19.0
1692      */
1693     public static ZonedDateTime toZonedDateTime(final Date date, final TimeZone timeZone) {
1694         return ZonedDateTime.ofInstant(date.toInstant(), toZoneId(timeZone));
1695     }
1696 
1697     private static ZoneId toZoneId(final TimeZone timeZone) {
1698         return TimeZones.toTimeZone(timeZone).toZoneId();
1699     }
1700 
1701     /**
1702      * Truncates a date, leaving the field specified as the most
1703      * significant field.
1704      *
1705      * <p>For example, if you had the date-time of 28 Mar 2002
1706      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
1707      * 2002 13:00:00.000.  If this was passed with MONTH, it would
1708      * return 1 Mar 2002 0:00:00.000.</p>
1709      *
1710      * @param date  the date to work with, not null.
1711      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1712      * @return the different truncated date, not null.
1713      * @throws NullPointerException if the date is {@code null}.
1714      * @throws ArithmeticException if the year is over 280 million.
1715      */
1716     public static Calendar truncate(final Calendar date, final int field) {
1717         Objects.requireNonNull(date, "date");
1718         return modify((Calendar) date.clone(), field, ModifyType.TRUNCATE);
1719     }
1720 
1721     /**
1722      * Truncates a date, leaving the field specified as the most
1723      * significant field.
1724      *
1725      * <p>For example, if you had the date-time of 28 Mar 2002
1726      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
1727      * 2002 13:00:00.000.  If this was passed with MONTH, it would
1728      * return 1 Mar 2002 0:00:00.000.</p>
1729      *
1730      * @param date  the date to work with, not null.
1731      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1732      * @return the different truncated date, not null.
1733      * @throws NullPointerException if the date is {@code null}.
1734      * @throws ArithmeticException if the year is over 280 million.
1735      */
1736     public static Date truncate(final Date date, final int field) {
1737         return modify(toCalendar(date), field, ModifyType.TRUNCATE).getTime();
1738     }
1739 
1740     /**
1741      * Truncates a date, leaving the field specified as the most
1742      * significant field.
1743      *
1744      * <p>For example, if you had the date-time of 28 Mar 2002
1745      * 13:45:01.231, if you passed with HOUR, it would return 28 Mar
1746      * 2002 13:00:00.000.  If this was passed with MONTH, it would
1747      * return 1 Mar 2002 0:00:00.000.</p>
1748      *
1749      * @param date  the date to work with, either {@link Date} or {@link Calendar}, not null.
1750      * @param field  the field from {@link Calendar} or {@code SEMI_MONTH}.
1751      * @return the different truncated date, not null.
1752      * @throws NullPointerException if the date is {@code null}.
1753      * @throws ClassCastException if the object type is not a {@link Date} or {@link Calendar}.
1754      * @throws ArithmeticException if the year is over 280 million.
1755      */
1756     public static Date truncate(final Object date, final int field) {
1757         Objects.requireNonNull(date, "date");
1758         if (date instanceof Date) {
1759             return truncate((Date) date, field);
1760         }
1761         if (date instanceof Calendar) {
1762             return truncate((Calendar) date, field).getTime();
1763         }
1764         throw new ClassCastException("Could not truncate " + date);
1765     }
1766 
1767     /**
1768      * Determines how two calendars compare up to no more than the specified
1769      * most significant field.
1770      *
1771      * @param cal1 the first calendar, not {@code null}.
1772      * @param cal2 the second calendar, not {@code null}.
1773      * @param field the field from {@link Calendar}.
1774      * @return a negative integer, zero, or a positive integer as the first
1775      * calendar is less than, equal to, or greater than the second.
1776      * @throws NullPointerException if any argument is {@code null}.
1777      * @see #truncate(Calendar, int)
1778      * @see #truncatedCompareTo(Date, Date, int)
1779      * @since 3.0
1780      */
1781     public static int truncatedCompareTo(final Calendar cal1, final Calendar cal2, final int field) {
1782         final Calendar truncatedCal1 = truncate(cal1, field);
1783         final Calendar truncatedCal2 = truncate(cal2, field);
1784         return truncatedCal1.compareTo(truncatedCal2);
1785     }
1786 
1787     /**
1788      * Determines how two dates compare up to no more than the specified
1789      * most significant field.
1790      *
1791      * @param date1 the first date, not {@code null}.
1792      * @param date2 the second date, not {@code null}.
1793      * @param field the field from {@link Calendar}.
1794      * @return a negative integer, zero, or a positive integer as the first
1795      * date is less than, equal to, or greater than the second.
1796      * @throws NullPointerException if any argument is {@code null}.
1797      * @see #truncate(Calendar, int)
1798      * @see #truncatedCompareTo(Date, Date, int)
1799      * @since 3.0
1800      */
1801     public static int truncatedCompareTo(final Date date1, final Date date2, final int field) {
1802         final Date truncatedDate1 = truncate(date1, field);
1803         final Date truncatedDate2 = truncate(date2, field);
1804         return truncatedDate1.compareTo(truncatedDate2);
1805     }
1806 
1807     /**
1808      * Determines if two calendars are equal up to no more than the specified
1809      * most significant field.
1810      *
1811      * @param cal1 the first calendar, not {@code null}.
1812      * @param cal2 the second calendar, not {@code null}.
1813      * @param field the field from {@link Calendar}.
1814      * @return {@code true} if equal; otherwise {@code false}.
1815      * @throws NullPointerException if any argument is {@code null}.
1816      * @see #truncate(Calendar, int)
1817      * @see #truncatedEquals(Date, Date, int)
1818      * @since 3.0
1819      */
1820     public static boolean truncatedEquals(final Calendar cal1, final Calendar cal2, final int field) {
1821         return truncatedCompareTo(cal1, cal2, field) == 0;
1822     }
1823 
1824     /**
1825      * Determines if two dates are equal up to no more than the specified
1826      * most significant field.
1827      *
1828      * @param date1 the first date, not {@code null}.
1829      * @param date2 the second date, not {@code null}.
1830      * @param field the field from {@link Calendar}.
1831      * @return {@code true} if equal; otherwise {@code false}.
1832      * @throws NullPointerException if any argument is {@code null}.
1833      * @see #truncate(Date, int)
1834      * @see #truncatedEquals(Calendar, Calendar, int)
1835      * @since 3.0
1836      */
1837     public static boolean truncatedEquals(final Date date1, final Date date2, final int field) {
1838         return truncatedCompareTo(date1, date2, field) == 0;
1839     }
1840 
1841     /**
1842      * @param date Date to validate.
1843      * @throws NullPointerException if {@code date == null}
1844      */
1845     private static void validateDateNotNull(final Date date) {
1846         Objects.requireNonNull(date, "date");
1847     }
1848 
1849     /**
1850      * {@link DateUtils} instances should NOT be constructed in
1851      * standard programming. Instead, the static methods on the class should
1852      * be used, such as {@code DateUtils.parseDate(str);}.
1853      *
1854      * <p>This constructor is public to permit tools that require a JavaBean
1855      * instance to operate.</p>
1856      *
1857      * @deprecated TODO Make private in 4.0.
1858      */
1859     @Deprecated
1860     public DateUtils() {
1861         // empty
1862     }
1863 
1864 }