1 /* Copyright 2002-2016 CS Systèmes d'Information
2 * Licensed to CS Systèmes d'Information (CS) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * CS 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 * http://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.orekit.time;
18
19 import java.io.Serializable;
20 import java.text.DecimalFormat;
21 import java.util.regex.Matcher;
22 import java.util.regex.Pattern;
23
24 import org.orekit.errors.OrekitIllegalArgumentException;
25 import org.orekit.errors.OrekitMessages;
26
27 /** Class representing a date broken up as year, month and day components.
28 * <p>This class uses the astronomical convention for calendars,
29 * which is also the convention used by <code>java.util.Date</code>:
30 * a year zero is present between years -1 and +1, and 10 days are
31 * missing in 1582. The calendar used around these special dates are:</p>
32 * <ul>
33 * <li>up to 0000-12-31 : proleptic julian calendar</li>
34 * <li>from 0001-01-01 to 1582-10-04: julian calendar</li>
35 * <li>from 1582-10-15: gregorian calendar</li>
36 * </ul>
37 * <p>Instances of this class are guaranteed to be immutable.</p>
38 * @see TimeComponents
39 * @see DateTimeComponents
40 * @author Luc Maisonobe
41 */
42 public class DateComponents implements Serializable, Comparable<DateComponents> {
43
44 /** Reference epoch for julian dates: -4712-01-01.
45 * <p>Both <code>java.util.Date</code> and {@link DateComponents} classes
46 * follow the astronomical conventions and consider a year 0 between
47 * years -1 and +1, hence this reference date lies in year -4712 and not
48 * in year -4713 as can be seen in other documents or programs that obey
49 * a different convention (for example the <code>convcal</code> utility).</p>
50 */
51 public static final DateComponents JULIAN_EPOCH;
52
53 /** Reference epoch for modified julian dates: 1858-11-17. */
54 public static final DateComponents MODIFIED_JULIAN_EPOCH;
55
56 /** Reference epoch for 1950 dates: 1950-01-01. */
57 public static final DateComponents FIFTIES_EPOCH;
58
59 /** Reference epoch for CCSDS Time Code Format (CCSDS 301.0-B-4): 1958-01-01. */
60 public static final DateComponents CCSDS_EPOCH;
61
62 /** Reference epoch for Galileo System Time: 1999-08-22. */
63 public static final DateComponents GALILEO_EPOCH;
64
65 /** Reference epoch for GPS weeks: 1980-01-06. */
66 public static final DateComponents GPS_EPOCH;
67
68 /** J2000.0 Reference epoch: 2000-01-01. */
69 public static final DateComponents J2000_EPOCH;
70
71 /** Java Reference epoch: 1970-01-01. */
72 public static final DateComponents JAVA_EPOCH;
73
74 /** Serializable UID. */
75 private static final long serialVersionUID = -2462694707837970938L;
76
77 /** Factory for proleptic julian calendar (up to 0000-12-31). */
78 private static final YearFactory PROLEPTIC_JULIAN_FACTORY = new ProlepticJulianFactory();
79
80 /** Factory for julian calendar (from 0001-01-01 to 1582-10-04). */
81 private static final YearFactory JULIAN_FACTORY = new JulianFactory();
82
83 /** Factory for gregorian calendar (from 1582-10-15). */
84 private static final YearFactory GREGORIAN_FACTORY = new GregorianFactory();
85
86 /** Factory for leap years. */
87 private static final MonthDayFactory LEAP_YEAR_FACTORY = new LeapYearFactory();
88
89 /** Factory for non-leap years. */
90 private static final MonthDayFactory COMMON_YEAR_FACTORY = new CommonYearFactory();
91
92 /** Format for years. */
93 private static final DecimalFormat FOUR_DIGITS = new DecimalFormat("0000");
94
95 /** Format for months and days. */
96 private static final DecimalFormat TWO_DIGITS = new DecimalFormat("00");
97
98 /** Offset between J2000 epoch and modified julian day epoch. */
99 private static final int MJD_TO_J2000 = 51544;
100
101 /** Basic and extended format calendar date. */
102 private static Pattern CALENDAR_FORMAT = Pattern.compile("^(-?\\d\\d\\d\\d)-?(\\d\\d)-?(\\d\\d)$");
103
104 /** Basic and extended format ordinal date. */
105 private static Pattern ORDINAL_FORMAT = Pattern.compile("^(-?\\d\\d\\d\\d)-?(\\d\\d\\d)$");
106
107 /** Basic and extended format week date. */
108 private static Pattern WEEK_FORMAT = Pattern.compile("^(-?\\d\\d\\d\\d)-?W(\\d\\d)-?(\\d)$");
109
110 static {
111 // this static statement makes sure the reference epoch are initialized
112 // once AFTER the various factories have been set up
113 JULIAN_EPOCH = new DateComponents(-4712, 1, 1);
114 MODIFIED_JULIAN_EPOCH = new DateComponents(1858, 11, 17);
115 FIFTIES_EPOCH = new DateComponents(1950, 1, 1);
116 CCSDS_EPOCH = new DateComponents(1958, 1, 1);
117 GALILEO_EPOCH = new DateComponents(1999, 8, 22);
118 GPS_EPOCH = new DateComponents(1980, 1, 6);
119 J2000_EPOCH = new DateComponents(2000, 1, 1);
120 JAVA_EPOCH = new DateComponents(1970, 1, 1);
121 }
122
123 /** Year number. */
124 private final int year;
125
126 /** Month number. */
127 private final int month;
128
129 /** Day number. */
130 private final int day;
131
132 /** Build a date from its components.
133 * @param year year number (may be 0 or negative for BC years)
134 * @param month month number from 1 to 12
135 * @param day day number from 1 to 31
136 * @exception IllegalArgumentException if inconsistent arguments
137 * are given (parameters out of range, february 29 for non-leap years,
138 * dates during the gregorian leap in 1582 ...)
139 */
140 public DateComponents(final int year, final int month, final int day)
141 throws IllegalArgumentException {
142
143 // very rough range check
144 // (just to avoid ArrayOutOfboundException in MonthDayFactory later)
145 if ((month < 1) || (month > 12)) {
146 throw new OrekitIllegalArgumentException(OrekitMessages.NON_EXISTENT_MONTH, month);
147 }
148
149 // start by trusting the parameters
150 this.year = year;
151 this.month = month;
152 this.day = day;
153
154 // build a check date from the J2000 day
155 final DateComponents check = new DateComponents(getJ2000Day());
156
157 // check the parameters for mismatch
158 // (i.e. invalid date components, like 29 february on non-leap years)
159 if ((year != check.year) || (month != check.month) || (day != check.day)) {
160 throw new OrekitIllegalArgumentException(OrekitMessages.NON_EXISTENT_YEAR_MONTH_DAY,
161 year, month, day);
162 }
163
164 }
165
166 /** Build a date from its components.
167 * @param year year number (may be 0 or negative for BC years)
168 * @param month month enumerate
169 * @param day day number from 1 to 31
170 * @exception IllegalArgumentException if inconsistent arguments
171 * are given (parameters out of range, february 29 for non-leap years,
172 * dates during the gregorian leap in 1582 ...)
173 */
174 public DateComponents(final int year, final Month month, final int day)
175 throws IllegalArgumentException {
176 this(year, month.getNumber(), day);
177 }
178
179 /** Build a date from a year and day number.
180 * @param year year number (may be 0 or negative for BC years)
181 * @param dayNumber day number in the year from 1 to 366
182 * @exception IllegalArgumentException if dayNumber is out of range
183 * with respect to year
184 */
185 public DateComponents(final int year, final int dayNumber)
186 throws IllegalArgumentException {
187 this(J2000_EPOCH, new DateComponents(year - 1, 12, 31).getJ2000Day() + dayNumber);
188 if (dayNumber != getDayOfYear()) {
189 throw new OrekitIllegalArgumentException(OrekitMessages.NON_EXISTENT_DAY_NUMBER_IN_YEAR,
190 dayNumber, year);
191 }
192 }
193
194 /** Build a date from its offset with respect to a {@link #J2000_EPOCH}.
195 * @param offset offset with respect to a {@link #J2000_EPOCH}
196 * @see #getJ2000Day()
197 */
198 public DateComponents(final int offset) {
199
200 // we follow the astronomical convention for calendars:
201 // we consider a year zero and 10 days are missing in 1582
202 // from 1582-10-15: gregorian calendar
203 // from 0001-01-01 to 1582-10-04: julian calendar
204 // up to 0000-12-31 : proleptic julian calendar
205 YearFactory yFactory = GREGORIAN_FACTORY;
206 if (offset < -152384) {
207 if (offset > -730122) {
208 yFactory = JULIAN_FACTORY;
209 } else {
210 yFactory = PROLEPTIC_JULIAN_FACTORY;
211 }
212 }
213 year = yFactory.getYear(offset);
214 final int dayInYear = offset - yFactory.getLastJ2000DayOfYear(year - 1);
215
216 // handle month/day according to the year being a common or leap year
217 final MonthDayFactory mdFactory =
218 yFactory.isLeap(year) ? LEAP_YEAR_FACTORY : COMMON_YEAR_FACTORY;
219 month = mdFactory.getMonth(dayInYear);
220 day = mdFactory.getDay(dayInYear, month);
221
222 }
223
224 /** Build a date from its offset with respect to a reference epoch.
225 * <p>This constructor is mainly useful to build a date from a modified
226 * julian day (using {@link #MODIFIED_JULIAN_EPOCH}) or a GPS week number
227 * (using {@link #GPS_EPOCH}).</p>
228 * @param epoch reference epoch
229 * @param offset offset with respect to a reference epoch
230 * @see #DateComponents(int)
231 * @see #getMJD()
232 */
233 public DateComponents(final DateComponents epoch, final int offset) {
234 this(epoch.getJ2000Day() + offset);
235 }
236
237 /** Build a date from week components.
238 * <p>The calendar week number is a number between 1 and 52 or 53 depending
239 * on the year. Week 1 is defined by ISO as the one that includes the first
240 * Thursday of a year. Week 1 may therefore start the previous year and week
241 * 52 or 53 may end in the next year. As an example calendar date 1995-01-01
242 * corresponds to week date 1994-W52-7 (i.e. Sunday in the last week of 1994
243 * is in fact the first day of year 1995). This date would beAnother example is calendar date
244 * 1996-12-31 which corresponds to week date 1997-W01-2 (i.e. Tuesday in the
245 * first week of 1997 is in fact the last day of year 1996).</p>
246 * @param wYear year associated to week numbering
247 * @param week week number in year,from 1 to 52 or 53
248 * @param dayOfWeek day of week, from 1 (Monday) to 7 (Sunday)
249 * @return a builded date
250 * @exception IllegalArgumentException if inconsistent arguments
251 * are given (parameters out of range, week 53 on a 52 weeks year ...)
252 */
253 public static DateComponents createFromWeekComponents(final int wYear, final int week, final int dayOfWeek)
254 throws IllegalArgumentException {
255
256 final DateComponents firstWeekMonday = new DateComponents(getFirstWeekMonday(wYear));
257 final DateComponents d = new DateComponents(firstWeekMonday, 7 * week + dayOfWeek - 8);
258
259 // check the parameters for invalid date components
260 if ((week != d.getCalendarWeek()) || (dayOfWeek != d.getDayOfWeek())) {
261 throw new OrekitIllegalArgumentException(OrekitMessages.NON_EXISTENT_WEEK_DATE,
262 wYear, week, dayOfWeek);
263 }
264
265 return d;
266
267 }
268
269 /** Parse a string in ISO-8601 format to build a date.
270 * <p>The supported formats are:
271 * <ul>
272 * <li>basic format calendar date: YYYYMMDD</li>
273 * <li>extended format calendar date: YYYY-MM-DD</li>
274 * <li>basic format ordinal date: YYYYDDD</li>
275 * <li>extended format ordinal date: YYYY-DDD</li>
276 * <li>basic format week date: YYYYWwwD</li>
277 * <li>extended format week date: YYYY-Www-D</li>
278 * </ul>
279 * As shown by the list above, only the complete representations defined in section 4.1
280 * of ISO-8601 standard are supported, neither expended representations nor representations
281 * with reduced accuracy are supported.
282 * </p>
283 * <p>
284 * Parsing a single integer as a julian day is <em>not</em> supported as it may be ambiguous
285 * with either the basic format calendar date or the basic format ordinal date depending
286 * on the number of digits.
287 * </p>
288 * @param string string to parse
289 * @return a parsed date
290 * @exception IllegalArgumentException if string cannot be parsed
291 */
292 public static DateComponents parseDate(final String string) {
293
294 // is the date a calendar date ?
295 final Matcher calendarMatcher = CALENDAR_FORMAT.matcher(string);
296 if (calendarMatcher.matches()) {
297 return new DateComponents(Integer.parseInt(calendarMatcher.group(1)),
298 Integer.parseInt(calendarMatcher.group(2)),
299 Integer.parseInt(calendarMatcher.group(3)));
300 }
301
302 // is the date an ordinal date ?
303 final Matcher ordinalMatcher = ORDINAL_FORMAT.matcher(string);
304 if (ordinalMatcher.matches()) {
305 return new DateComponents(Integer.parseInt(ordinalMatcher.group(1)),
306 Integer.parseInt(ordinalMatcher.group(2)));
307 }
308
309 // is the date a week date ?
310 final Matcher weekMatcher = WEEK_FORMAT.matcher(string);
311 if (weekMatcher.matches()) {
312 return createFromWeekComponents(Integer.parseInt(weekMatcher.group(1)),
313 Integer.parseInt(weekMatcher.group(2)),
314 Integer.parseInt(weekMatcher.group(3)));
315 }
316
317 throw new OrekitIllegalArgumentException(OrekitMessages.NON_EXISTENT_DATE, string);
318
319 }
320
321 /** Get the year number.
322 * @return year number (may be 0 or negative for BC years)
323 */
324 public int getYear() {
325 return year;
326 }
327
328 /** Get the month.
329 * @return month number from 1 to 12
330 */
331 public int getMonth() {
332 return month;
333 }
334
335 /** Get the month as an enumerate.
336 * @return month as an enumerate
337 */
338 public Month getMonthEnum() {
339 return Month.getMonth(month);
340 }
341
342 /** Get the day.
343 * @return day number from 1 to 31
344 */
345 public int getDay() {
346 return day;
347 }
348
349 /** Get the day number with respect to J2000 epoch.
350 * @return day number with respect to J2000 epoch
351 */
352 public int getJ2000Day() {
353 YearFactory yFactory = GREGORIAN_FACTORY;
354 if (year < 1583) {
355 if (year < 1) {
356 yFactory = PROLEPTIC_JULIAN_FACTORY;
357 } else if ((year < 1582) || (month < 10) || ((month < 11) && (day < 5))) {
358 yFactory = JULIAN_FACTORY;
359 }
360 }
361 final MonthDayFactory mdFactory =
362 yFactory.isLeap(year) ? LEAP_YEAR_FACTORY : COMMON_YEAR_FACTORY;
363 return yFactory.getLastJ2000DayOfYear(year - 1) +
364 mdFactory.getDayInYear(month, day);
365 }
366
367 /** Get the modified julian day.
368 * @return modified julian day
369 */
370 public int getMJD() {
371 return MJD_TO_J2000 + getJ2000Day();
372 }
373
374 /** Get the calendar week number.
375 * <p>The calendar week number is a number between 1 and 52 or 53 depending
376 * on the year. Week 1 is defined by ISO as the one that includes the first
377 * Thursday of a year. Week 1 may therefore start the previous year and week
378 * 52 or 53 may end in the next year. As an example calendar date 1995-01-01
379 * corresponds to week date 1994-W52-7 (i.e. Sunday in the last week of 1994
380 * is in fact the first day of year 1995). Another example is calendar date
381 * 1996-12-31 which corresponds to week date 1997-W01-2 (i.e. Tuesday in the
382 * first week of 1997 is in fact the last day of year 1996).</p>
383 * @return calendar week number
384 */
385 public int getCalendarWeek() {
386 final int firstWeekMonday = getFirstWeekMonday(year);
387 int daysSincefirstMonday = getJ2000Day() - firstWeekMonday;
388 if (daysSincefirstMonday < 0) {
389 // we are still in a week from previous year
390 daysSincefirstMonday += firstWeekMonday - getFirstWeekMonday(year - 1);
391 } else if (daysSincefirstMonday > 363) {
392 // up to three days at end of year may belong to first week of next year
393 // (by chance, there is no need for a specific check in year 1582 ...)
394 final int weekYearLength = getFirstWeekMonday(year + 1) - firstWeekMonday;
395 if (daysSincefirstMonday >= weekYearLength) {
396 daysSincefirstMonday -= weekYearLength;
397 }
398 }
399 return 1 + daysSincefirstMonday / 7;
400 }
401
402 /** Get the monday of a year first week.
403 * @param year year to consider
404 * @return day of the monday of the first weak of year
405 */
406 private static int getFirstWeekMonday(final int year) {
407 final int yearFirst = new DateComponents(year, 1, 1).getJ2000Day();
408 final int offsetToMonday = 4 - (yearFirst + 2) % 7;
409 return yearFirst + offsetToMonday + ((offsetToMonday > 3) ? -7 : 0);
410 }
411
412 /** Get the day of week.
413 * <p>Day of week is a number between 1 (Monday) and 7 (Sunday).</p>
414 * @return day of week
415 */
416 public int getDayOfWeek() {
417 final int dow = (getJ2000Day() + 6) % 7; // result is between -6 and +6
418 return (dow < 1) ? (dow + 7) : dow;
419 }
420
421 /** Get the day number in year.
422 * <p>Day number in year is between 1 (January 1st) and either 365 or
423 * 366 inclusive depending on year.</p>
424 * @return day number in year
425 */
426 public int getDayOfYear() {
427 return getJ2000Day() - new DateComponents(year - 1, 12, 31).getJ2000Day();
428 }
429
430 /** Get a string representation (ISO-8601) of the date.
431 * @return string representation of the date.
432 */
433 public String toString() {
434 return new StringBuffer().
435 append(FOUR_DIGITS.format(year)).append('-').
436 append(TWO_DIGITS.format(month)).append('-').
437 append(TWO_DIGITS.format(day)).
438 toString();
439 }
440
441 /** {@inheritDoc} */
442 public int compareTo(final DateComponents other) {
443 final int j2000Day = getJ2000Day();
444 final int otherJ2000Day = other.getJ2000Day();
445 if (j2000Day < otherJ2000Day) {
446 return -1;
447 } else if (j2000Day > otherJ2000Day) {
448 return 1;
449 }
450 return 0;
451 }
452
453 /** {@inheritDoc} */
454 public boolean equals(final Object other) {
455 try {
456 final DateComponents otherDate = (DateComponents) other;
457 return (otherDate != null) && (year == otherDate.year) &&
458 (month == otherDate.month) && (day == otherDate.day);
459 } catch (ClassCastException cce) {
460 return false;
461 }
462 }
463
464 /** {@inheritDoc} */
465 public int hashCode() {
466 return (year << 16) ^ (month << 8) ^ day;
467 }
468
469 /** Interface for dealing with years sequences according to some calendar. */
470 private interface YearFactory {
471
472 /** Get the year number for a given day number with respect to J2000 epoch.
473 * @param j2000Day day number with respect to J2000 epoch
474 * @return year number
475 */
476 int getYear(int j2000Day);
477
478 /** Get the day number with respect to J2000 epoch for new year's Eve.
479 * @param year year number
480 * @return day number with respect to J2000 epoch for new year's Eve
481 */
482 int getLastJ2000DayOfYear(int year);
483
484 /** Check if a year is a leap or common year.
485 * @param year year number
486 * @return true if year is a leap year
487 */
488 boolean isLeap(int year);
489
490 }
491
492 /** Class providing a years sequence compliant with the proleptic julian calendar. */
493 private static class ProlepticJulianFactory implements YearFactory {
494
495 /** {@inheritDoc} */
496 public int getYear(final int j2000Day) {
497 return (int) -((-4l * j2000Day - 2920488l) / 1461l);
498 }
499
500 /** {@inheritDoc} */
501 public int getLastJ2000DayOfYear(final int year) {
502 return (1461 * year + 1) / 4 - 730123;
503 }
504
505 /** {@inheritDoc} */
506 public boolean isLeap(final int year) {
507 return (year % 4) == 0;
508 }
509
510 }
511
512 /** Class providing a years sequence compliant with the julian calendar. */
513 private static class JulianFactory implements YearFactory {
514
515 /** {@inheritDoc} */
516 public int getYear(final int j2000Day) {
517 return (int) ((4l * j2000Day + 2921948l) / 1461l);
518 }
519
520 /** {@inheritDoc} */
521 public int getLastJ2000DayOfYear(final int year) {
522 return (1461 * year) / 4 - 730122;
523 }
524
525 /** {@inheritDoc} */
526 public boolean isLeap(final int year) {
527 return (year % 4) == 0;
528 }
529
530 }
531
532 /** Class providing a years sequence compliant with the gregorian calendar. */
533 private static class GregorianFactory implements YearFactory {
534
535 /** {@inheritDoc} */
536 public int getYear(final int j2000Day) {
537
538 // year estimate
539 int year = (int) ((400l * j2000Day + 292194288l) / 146097l);
540
541 // the previous estimate is one unit too high in some rare cases
542 // (240 days in the 400 years gregorian cycle, about 0.16%)
543 if (j2000Day <= getLastJ2000DayOfYear(year - 1)) {
544 --year;
545 }
546
547 // exact year
548 return year;
549
550 }
551
552 /** {@inheritDoc} */
553 public int getLastJ2000DayOfYear(final int year) {
554 return (1461 * year) / 4 - year / 100 + year / 400 - 730120;
555 }
556
557 /** {@inheritDoc} */
558 public boolean isLeap(final int year) {
559 return ((year % 4) == 0) && (((year % 400) == 0) || ((year % 100) != 0));
560 }
561
562 }
563
564 /** Interface for dealing with months sequences according to leap/common years. */
565 private interface MonthDayFactory {
566
567 /** Get the month number for a given day number within year.
568 * @param dayInYear day number within year
569 * @return month number
570 */
571 int getMonth(int dayInYear);
572
573 /** Get the day number for given month and day number within year.
574 * @param dayInYear day number within year
575 * @param month month number
576 * @return day number
577 */
578 int getDay(int dayInYear, int month);
579
580 /** Get the day number within year for given month and day numbers.
581 * @param month month number
582 * @param day day number
583 * @return day number within year
584 */
585 int getDayInYear(int month, int day);
586
587 }
588
589 /** Class providing the months sequence for leap years. */
590 private static class LeapYearFactory implements MonthDayFactory {
591
592 /** Months succession definition. */
593 private static final int[] PREVIOUS_MONTH_END_DAY = {
594 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335
595 };
596
597 /** {@inheritDoc} */
598 public int getMonth(final int dayInYear) {
599 return (dayInYear < 32) ? 1 : (10 * dayInYear + 313) / 306;
600 }
601
602 /** {@inheritDoc} */
603 public int getDay(final int dayInYear, final int month) {
604 return dayInYear - PREVIOUS_MONTH_END_DAY[month];
605 }
606
607 /** {@inheritDoc} */
608 public int getDayInYear(final int month, final int day) {
609 return day + PREVIOUS_MONTH_END_DAY[month];
610 }
611
612 }
613
614 /** Class providing the months sequence for common years. */
615 private static class CommonYearFactory implements MonthDayFactory {
616
617 /** Months succession definition. */
618 private static final int[] PREVIOUS_MONTH_END_DAY = {
619 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
620 };
621
622 /** {@inheritDoc} */
623 public int getMonth(final int dayInYear) {
624 return (dayInYear < 32) ? 1 : (10 * dayInYear + 323) / 306;
625 }
626
627 /** {@inheritDoc} */
628 public int getDay(final int dayInYear, final int month) {
629 return dayInYear - PREVIOUS_MONTH_END_DAY[month];
630 }
631
632 /** {@inheritDoc} */
633 public int getDayInYear(final int month, final int day) {
634 return day + PREVIOUS_MONTH_END_DAY[month];
635 }
636
637 }
638
639 }