xref: /webtrees/app/Date/AbstractCalendarDate.php (revision 090a06287954f43677f06ea778b3f67c029de8fe)
1<?php
2
3/**
4 * webtrees: online genealogy
5 * Copyright (C) 2021 webtrees development team
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <https://www.gnu.org/licenses/>.
16 */
17
18declare(strict_types=1);
19
20namespace Fisharebest\Webtrees\Date;
21
22use Fisharebest\ExtCalendar\CalendarInterface;
23use Fisharebest\ExtCalendar\JewishCalendar;
24use Fisharebest\Webtrees\Carbon;
25use Fisharebest\Webtrees\Http\RequestHandlers\CalendarPage;
26use Fisharebest\Webtrees\I18N;
27use Fisharebest\Webtrees\Tree;
28use InvalidArgumentException;
29
30use function array_key_exists;
31use function array_search;
32use function get_class;
33use function intdiv;
34use function is_array;
35use function is_int;
36use function max;
37use function preg_match;
38use function route;
39use function sprintf;
40use function str_contains;
41use function strpbrk;
42use function strtr;
43use function trigger_error;
44use function trim;
45use function view;
46
47use const E_USER_DEPRECATED;
48
49/**
50 * Classes for Gedcom Date/Calendar functionality.
51 *
52 * CalendarDate is a base class for classes such as GregorianDate, etc.
53 * + All supported calendars have non-zero days/months/years.
54 * + We store dates as both Y/M/D and Julian Days.
55 * + For imprecise dates such as "JAN 2000" we store the start/end julian day.
56 *
57 * NOTE: Since different calendars start their days at different times, (civil
58 * midnight, solar midnight, sunset, sunrise, etc.), we convert on the basis of
59 * midday.
60 */
61abstract class AbstractCalendarDate
62{
63    // GEDCOM calendar escape
64    public const ESCAPE = '@#DUNKNOWN@';
65
66    // Convert GEDCOM month names to month numbers.
67    protected const MONTH_ABBREVIATIONS = [];
68
69    /** @var CalendarInterface The calendar system used to represent this date */
70    protected $calendar;
71
72    /** @var int Year number */
73    public $year;
74
75    /** @var int Month number */
76    public $month;
77
78    /** @var int Day number */
79    public $day;
80
81    /** @var int Earliest Julian day number (start of month/year for imprecise dates) */
82    private $minimum_julian_day;
83
84    /** @var int Latest Julian day number (end of month/year for imprecise dates) */
85    private $maximum_julian_day;
86
87    /**
88     * Create a date from either:
89     * a Julian day number
90     * day/month/year strings from a GEDCOM date
91     * another CalendarDate object
92     *
93     * @param array<string>|int|AbstractCalendarDate $date
94     */
95    protected function __construct($date)
96    {
97        // Construct from an integer (a julian day number)
98        if (is_int($date)) {
99            $this->minimum_julian_day = $date;
100            $this->maximum_julian_day = $date;
101            [$this->year, $this->month, $this->day] = $this->calendar->jdToYmd($date);
102
103            return;
104        }
105
106        // Construct from an array (of three gedcom-style strings: "1900", "FEB", "4")
107        if (is_array($date)) {
108            $this->day = (int) $date[2];
109            if (array_key_exists($date[1], static::MONTH_ABBREVIATIONS)) {
110                $this->month = static::MONTH_ABBREVIATIONS[$date[1]];
111            } else {
112                $this->month = 0;
113                $this->day   = 0;
114            }
115            $this->year = $this->extractYear($date[0]);
116
117            // Our simple lookup table above does not take into account Adar and leap-years.
118            if ($this->month === 6 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->year)) {
119                $this->month = 7;
120            }
121
122            $this->setJdFromYmd();
123
124            return;
125        }
126
127        // Construct from a CalendarDate
128        $this->minimum_julian_day = $date->minimum_julian_day;
129        $this->maximum_julian_day = $date->maximum_julian_day;
130
131        // Construct from an equivalent xxxxDate object
132        if (get_class($this) === get_class($date)) {
133            $this->year  = $date->year;
134            $this->month = $date->month;
135            $this->day   = $date->day;
136
137            return;
138        }
139
140        // Not all dates can be converted
141        if (!$this->inValidRange()) {
142            $this->year  = 0;
143            $this->month = 0;
144            $this->day   = 0;
145
146            return;
147        }
148
149        // ...else construct an inequivalent xxxxDate object
150        if ($date->year === 0) {
151            // Incomplete date - convert on basis of anniversary in current year
152            $today = $date->calendar->jdToYmd(Carbon::now()->julianDay());
153            $jd    = $date->calendar->ymdToJd($today[0], $date->month, $date->day === 0 ? $today[2] : $date->day);
154        } else {
155            // Complete date
156            $jd = intdiv($date->maximum_julian_day + $date->minimum_julian_day, 2);
157        }
158        [$this->year, $this->month, $this->day] = $this->calendar->jdToYmd($jd);
159        // New date has same precision as original date
160        if ($date->year === 0) {
161            $this->year = 0;
162        }
163        if ($date->month === 0) {
164            $this->month = 0;
165        }
166        if ($date->day === 0) {
167            $this->day = 0;
168        }
169        $this->setJdFromYmd();
170    }
171
172    /**
173     * @return int
174     */
175    public function maximumJulianDay(): int
176    {
177        return $this->maximum_julian_day;
178    }
179
180    /**
181     * @return int
182     */
183    public function year(): int
184    {
185        return $this->year;
186    }
187
188    /**
189     * @return int
190     */
191    public function month(): int
192    {
193        return $this->month;
194    }
195
196    /**
197     * @return int
198     */
199    public function day(): int
200    {
201        return $this->day;
202    }
203
204    /**
205     * @return int
206     */
207    public function minimumJulianDay(): int
208    {
209        return $this->minimum_julian_day;
210    }
211
212    /**
213     * Is the current year a leap year?
214     *
215     * @return bool
216     */
217    public function isLeapYear(): bool
218    {
219        return $this->calendar->isLeapYear($this->year);
220    }
221
222    /**
223     * Set the object’s Julian day number from a potentially incomplete year/month/day
224     *
225     * @return void
226     */
227    public function setJdFromYmd(): void
228    {
229        if ($this->year === 0) {
230            $this->minimum_julian_day = 0;
231            $this->maximum_julian_day = 0;
232        } elseif ($this->month === 0) {
233            $this->minimum_julian_day = $this->calendar->ymdToJd($this->year, 1, 1);
234            $this->maximum_julian_day = $this->calendar->ymdToJd($this->nextYear($this->year), 1, 1) - 1;
235        } elseif ($this->day === 0) {
236            [$ny, $nm] = $this->nextMonth();
237            $this->minimum_julian_day = $this->calendar->ymdToJd($this->year, $this->month, 1);
238            $this->maximum_julian_day = $this->calendar->ymdToJd($ny, $nm, 1) - 1;
239        } else {
240            $this->minimum_julian_day = $this->calendar->ymdToJd($this->year, $this->month, $this->day);
241            $this->maximum_julian_day = $this->minimum_julian_day;
242        }
243    }
244
245    /**
246     * Full day of the week
247     *
248     * @param int $day_number
249     *
250     * @return string
251     */
252    public function dayNames(int $day_number): string
253    {
254        static $translated_day_names;
255
256        if ($translated_day_names === null) {
257            $translated_day_names = [
258                0 => I18N::translate('Monday'),
259                1 => I18N::translate('Tuesday'),
260                2 => I18N::translate('Wednesday'),
261                3 => I18N::translate('Thursday'),
262                4 => I18N::translate('Friday'),
263                5 => I18N::translate('Saturday'),
264                6 => I18N::translate('Sunday'),
265            ];
266        }
267
268        return $translated_day_names[$day_number];
269    }
270
271    /**
272     * Abbreviated day of the week
273     *
274     * @param int $day_number
275     *
276     * @return string
277     */
278    protected function dayNamesAbbreviated(int $day_number): string
279    {
280        static $translated_day_names;
281
282        if ($translated_day_names === null) {
283            $translated_day_names = [
284                /* I18N: abbreviation for Monday */
285                0 => I18N::translate('Mon'),
286                /* I18N: abbreviation for Tuesday */
287                1 => I18N::translate('Tue'),
288                /* I18N: abbreviation for Wednesday */
289                2 => I18N::translate('Wed'),
290                /* I18N: abbreviation for Thursday */
291                3 => I18N::translate('Thu'),
292                /* I18N: abbreviation for Friday */
293                4 => I18N::translate('Fri'),
294                /* I18N: abbreviation for Saturday */
295                5 => I18N::translate('Sat'),
296                /* I18N: abbreviation for Sunday */
297                6 => I18N::translate('Sun'),
298            ];
299        }
300
301        return $translated_day_names[$day_number];
302    }
303
304    /**
305     * Most years are 1 more than the previous, but not always (e.g. 1BC->1AD)
306     *
307     * @param int $year
308     *
309     * @return int
310     */
311    protected function nextYear(int $year): int
312    {
313        return $year + 1;
314    }
315
316    /**
317     * Calendars that use suffixes, etc. (e.g. “B.C.”) or OS/NS notation should redefine this.
318     *
319     * @param string $year
320     *
321     * @return int
322     */
323    protected function extractYear(string $year): int
324    {
325        return (int) $year;
326    }
327
328    /**
329     * Compare two dates, for sorting
330     *
331     * @param AbstractCalendarDate $d1
332     * @param AbstractCalendarDate $d2
333     *
334     * @return int
335     */
336    public static function compare(AbstractCalendarDate $d1, AbstractCalendarDate $d2): int
337    {
338        if ($d1->maximum_julian_day < $d2->minimum_julian_day) {
339            return -1;
340        }
341
342        if ($d2->maximum_julian_day < $d1->minimum_julian_day) {
343            return 1;
344        }
345
346        return 0;
347    }
348
349    /**
350     * Calculate the years/months/days between this date and another date.
351     * Results assume you add the days first, then the months.
352     * 4 February -> 3 July is 27 days (3 March) and 4 months.
353     * It is not 4 months (4 June) and 29 days.
354     *
355     * @param AbstractCalendarDate $date
356     *
357     * @return int[] Age in years/months/days
358     */
359    public function ageDifference(AbstractCalendarDate $date): array
360    {
361        // Incomplete dates
362        if ($this->year === 0 || $date->year === 0) {
363            return [-1, -1, -1];
364        }
365
366        // Overlapping dates
367        if (self::compare($this, $date) === 0) {
368            return [0, 0, 0];
369        }
370
371        // Perform all calculations using the calendar of the first date
372        [$year1, $month1, $day1] = $this->calendar->jdToYmd($this->minimum_julian_day);
373        [$year2, $month2, $day2] = $this->calendar->jdToYmd($date->minimum_julian_day);
374
375        $years  = $year2 - $year1;
376        $months = $month2 - $month1;
377        $days   = $day2 - $day1;
378
379        if ($days < 0) {
380            $days += $this->calendar->daysInMonth($year1, $month1);
381            $months--;
382        }
383
384        if ($months < 0) {
385            $months += $this->calendar->monthsInYear($year2);
386            $years--;
387        }
388
389        return [$years, $months, $days];
390    }
391
392    /**
393     * Convert a date from one calendar to another.
394     *
395     * @param string $calendar
396     *
397     * @return AbstractCalendarDate
398     */
399    public function convertToCalendar(string $calendar): AbstractCalendarDate
400    {
401        switch ($calendar) {
402            case 'gregorian':
403                return new GregorianDate($this);
404            case 'julian':
405                return new JulianDate($this);
406            case 'jewish':
407                return new JewishDate($this);
408            case 'french':
409                return new FrenchDate($this);
410            case 'hijri':
411                return new HijriDate($this);
412            case 'jalali':
413                return new JalaliDate($this);
414            default:
415                return $this;
416        }
417    }
418
419    /**
420     * Is this date within the valid range of the calendar
421     *
422     * @return bool
423     */
424    public function inValidRange(): bool
425    {
426        return $this->minimum_julian_day >= $this->calendar->jdStart() && $this->maximum_julian_day <= $this->calendar->jdEnd();
427    }
428
429    /**
430     * How many months in a year
431     *
432     * @return int
433     */
434    public function monthsInYear(): int
435    {
436        return $this->calendar->monthsInYear();
437    }
438
439    /**
440     * How many days in the current month
441     *
442     * @return int
443     */
444    public function daysInMonth(): int
445    {
446        try {
447            return $this->calendar->daysInMonth($this->year, $this->month);
448        } catch (InvalidArgumentException $ex) {
449            // calendar.php calls this with "DD MMM" dates, for which we cannot calculate
450            // the length of a month. Should we validate this before calling this function?
451            return 0;
452        }
453    }
454
455    /**
456     * How many days in the current week
457     *
458     * @return int
459     */
460    public function daysInWeek(): int
461    {
462        return $this->calendar->daysInWeek();
463    }
464
465    /**
466     * Format a date, using similar codes to the PHP date() function.
467     *
468     * @param string $format    See http://php.net/date
469     * @param string $qualifier GEDCOM qualifier, so we can choose the right case for the month name.
470     *
471     * @return string
472     */
473    public function format(string $format, string $qualifier = ''): string
474    {
475        // Dates can include additional punctuation and symbols. e.g.
476        // %F %j, %Y
477        // %Y. %F %d.
478        // %Y年 %n月 %j日
479        // %j. %F %Y
480        // Don’t show exact details or unnecessary punctuation for inexact dates.
481        if ($this->day === 0) {
482            $format = strtr($format, ['%d' => '', '%j日' => '', '%j,' => '', '%j' => '', '%l' => '', '%D' => '', '%N' => '', '%S' => '', '%w' => '', '%z' => '']);
483        }
484        if ($this->month === 0) {
485            $format = strtr($format, ['%F' => '', '%m' => '', '%M' => '', '年 %n月' => '', '%n' => '', '%t' => '']);
486        }
487        if ($this->year === 0) {
488            $format = strtr($format, ['%t' => '', '%L' => '', '%G' => '', '%y' => '', '%Y年' => '', '%Y' => '']);
489        }
490        $format = trim($format, ',. /-');
491
492        if ($this->day !== 0 && preg_match('/%[djlDNSwz]/', $format)) {
493            // If we have a day-number *and* we are being asked to display it, then genitive
494            $case = 'GENITIVE';
495        } else {
496            switch ($qualifier) {
497                case 'TO':
498                case 'ABT':
499                case 'FROM':
500                    $case = 'GENITIVE';
501                    break;
502                case 'AFT':
503                    $case = 'LOCATIVE';
504                    break;
505                case 'BEF':
506                case 'BET':
507                case 'AND':
508                    $case = 'INSTRUMENTAL';
509                    break;
510                case '':
511                case 'INT':
512                case 'EST':
513                case 'CAL':
514                default: // There shouldn't be any other options...
515                    $case = 'NOMINATIVE';
516                    break;
517            }
518        }
519        // Build up the formatted date, character at a time
520        if (str_contains($format, '%d')) {
521            $format = strtr($format, ['%d' => $this->formatDayZeros()]);
522        }
523        if (str_contains($format, '%j')) {
524            $format = strtr($format, ['%j' => $this->formatDay()]);
525        }
526        if (str_contains($format, '%l')) {
527            $format = strtr($format, ['%l' => $this->formatLongWeekday()]);
528        }
529        if (str_contains($format, '%D')) {
530            $format = strtr($format, ['%D' => $this->formatShortWeekday()]);
531        }
532        if (str_contains($format, '%N')) {
533            $format = strtr($format, ['%N' => $this->formatIsoWeekday()]);
534        }
535        if (str_contains($format, '%w')) {
536            $format = strtr($format, ['%w' => $this->formatNumericWeekday()]);
537        }
538        if (str_contains($format, '%z')) {
539            $format = strtr($format, ['%z' => $this->formatDayOfYear()]);
540        }
541        if (str_contains($format, '%F')) {
542            $format = strtr($format, ['%F' => $this->formatLongMonth($case)]);
543        }
544        if (str_contains($format, '%m')) {
545            $format = strtr($format, ['%m' => $this->formatMonthZeros()]);
546        }
547        if (str_contains($format, '%M')) {
548            $format = strtr($format, ['%M' => $this->formatShortMonth()]);
549        }
550        if (str_contains($format, '%n')) {
551            $format = strtr($format, ['%n' => $this->formatMonth()]);
552        }
553        if (str_contains($format, '%t')) {
554            $format = strtr($format, ['%t' => (string) $this->daysInMonth()]);
555        }
556        if (str_contains($format, '%L')) {
557            $format = strtr($format, ['%L' => $this->isLeapYear() ? '1' : '0']);
558        }
559        if (str_contains($format, '%Y')) {
560            $format = strtr($format, ['%Y' => $this->formatLongYear()]);
561        }
562        if (str_contains($format, '%y')) {
563            $format = strtr($format, ['%y' => $this->formatShortYear()]);
564        }
565        // These 4 extensions are useful for re-formatting gedcom dates.
566        if (str_contains($format, '%@')) {
567            $format = strtr($format, ['%@' => $this->formatGedcomCalendarEscape()]);
568        }
569        if (str_contains($format, '%A')) {
570            $format = strtr($format, ['%A' => $this->formatGedcomDay()]);
571        }
572        if (str_contains($format, '%O')) {
573            $format = strtr($format, ['%O' => $this->formatGedcomMonth()]);
574        }
575        if (str_contains($format, '%E')) {
576            $format = strtr($format, ['%E' => $this->formatGedcomYear()]);
577        }
578
579        return $format;
580    }
581
582    /**
583     * Generate the %d format for a date.
584     *
585     * @return string
586     */
587    protected function formatDayZeros(): string
588    {
589        if ($this->day > 9) {
590            return I18N::digits($this->day);
591        }
592
593        return I18N::digits('0' . $this->day);
594    }
595
596    /**
597     * Generate the %j format for a date.
598     *
599     * @return string
600     */
601    protected function formatDay(): string
602    {
603        return I18N::digits($this->day);
604    }
605
606    /**
607     * Generate the %l format for a date.
608     *
609     * @return string
610     */
611    protected function formatLongWeekday(): string
612    {
613        return $this->dayNames($this->minimum_julian_day % $this->calendar->daysInWeek());
614    }
615
616    /**
617     * Generate the %D format for a date.
618     *
619     * @return string
620     */
621    protected function formatShortWeekday(): string
622    {
623        return $this->dayNamesAbbreviated($this->minimum_julian_day % $this->calendar->daysInWeek());
624    }
625
626    /**
627     * Generate the %N format for a date.
628     *
629     * @return string
630     */
631    protected function formatIsoWeekday(): string
632    {
633        return I18N::digits($this->minimum_julian_day % 7 + 1);
634    }
635
636    /**
637     * Generate the %w format for a date.
638     *
639     * @return string
640     */
641    protected function formatNumericWeekday(): string
642    {
643        return I18N::digits(($this->minimum_julian_day + 1) % $this->calendar->daysInWeek());
644    }
645
646    /**
647     * Generate the %z format for a date.
648     *
649     * @return string
650     */
651    protected function formatDayOfYear(): string
652    {
653        return I18N::digits($this->minimum_julian_day - $this->calendar->ymdToJd($this->year, 1, 1));
654    }
655
656    /**
657     * Generate the %n format for a date.
658     *
659     * @return string
660     */
661    protected function formatMonth(): string
662    {
663        return I18N::digits($this->month);
664    }
665
666    /**
667     * Generate the %m format for a date.
668     *
669     * @return string
670     */
671    protected function formatMonthZeros(): string
672    {
673        if ($this->month > 9) {
674            return I18N::digits($this->month);
675        }
676
677        return I18N::digits('0' . $this->month);
678    }
679
680    /**
681     * Generate the %F format for a date.
682     *
683     * @param string $case Which grammatical case shall we use
684     *
685     * @return string
686     */
687    protected function formatLongMonth($case = 'NOMINATIVE'): string
688    {
689        switch ($case) {
690            case 'GENITIVE':
691                return $this->monthNameGenitiveCase($this->month, $this->isLeapYear());
692            case 'NOMINATIVE':
693                return $this->monthNameNominativeCase($this->month, $this->isLeapYear());
694            case 'LOCATIVE':
695                return $this->monthNameLocativeCase($this->month, $this->isLeapYear());
696            case 'INSTRUMENTAL':
697                return $this->monthNameInstrumentalCase($this->month, $this->isLeapYear());
698            default:
699                throw new InvalidArgumentException($case);
700        }
701    }
702
703    /**
704     * Full month name in genitive case.
705     *
706     * @param int  $month
707     * @param bool $leap_year Some calendars use leap months
708     *
709     * @return string
710     */
711    abstract protected function monthNameGenitiveCase(int $month, bool $leap_year): string;
712
713    /**
714     * Full month name in nominative case.
715     *
716     * @param int  $month
717     * @param bool $leap_year Some calendars use leap months
718     *
719     * @return string
720     */
721    abstract protected function monthNameNominativeCase(int $month, bool $leap_year): string;
722
723    /**
724     * Full month name in locative case.
725     *
726     * @param int  $month
727     * @param bool $leap_year Some calendars use leap months
728     *
729     * @return string
730     */
731    abstract protected function monthNameLocativeCase(int $month, bool $leap_year): string;
732
733    /**
734     * Full month name in instrumental case.
735     *
736     * @param int  $month
737     * @param bool $leap_year Some calendars use leap months
738     *
739     * @return string
740     */
741    abstract protected function monthNameInstrumentalCase(int $month, bool $leap_year): string;
742
743    /**
744     * Abbreviated month name
745     *
746     * @param int  $month
747     * @param bool $leap_year Some calendars use leap months
748     *
749     * @return string
750     */
751    abstract protected function monthNameAbbreviated(int $month, bool $leap_year): string;
752
753    /**
754     * Generate the %M format for a date.
755     *
756     * @return string
757     */
758    protected function formatShortMonth(): string
759    {
760        return $this->monthNameAbbreviated($this->month, $this->isLeapYear());
761    }
762
763    /**
764     * Generate the %y format for a date.
765     * NOTE Short year is NOT a 2-digit year. It is for calendars such as hebrew
766     * which have a 3-digit form of 4-digit years.
767     *
768     * @return string
769     */
770    protected function formatShortYear(): string
771    {
772        return $this->formatLongYear();
773    }
774
775    /**
776     * Generate the %A format for a date.
777     *
778     * @return string
779     */
780    protected function formatGedcomDay(): string
781    {
782        if ($this->day === 0) {
783            return '';
784        }
785
786        return sprintf('%02d', $this->day);
787    }
788
789    /**
790     * Generate the %O format for a date.
791     *
792     * @return string
793     */
794    protected function formatGedcomMonth(): string
795    {
796        // Our simple lookup table doesn't work correctly for Adar on leap years
797        if ($this->month === 7 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->year)) {
798            return 'ADR';
799        }
800
801        return array_search($this->month, static::MONTH_ABBREVIATIONS, true);
802    }
803
804    /**
805     * Generate the %E format for a date.
806     *
807     * @return string
808     */
809    protected function formatGedcomYear(): string
810    {
811        if ($this->year === 0) {
812            return '';
813        }
814
815        return sprintf('%04d', $this->year);
816    }
817
818    /**
819     * Generate the %@ format for a calendar escape.
820     *
821     * @return string
822     */
823    protected function formatGedcomCalendarEscape(): string
824    {
825        return static::ESCAPE;
826    }
827
828    /**
829     * Generate the %Y format for a date.
830     *
831     * @return string
832     */
833    protected function formatLongYear(): string
834    {
835        return I18N::digits($this->year);
836    }
837
838    /**
839     * Which months follows this one? Calendars with leap-months should provide their own implementation.
840     *
841     * @return int[]
842     */
843    protected function nextMonth(): array
844    {
845        return [
846            $this->month === $this->calendar->monthsInYear() ? $this->nextYear($this->year) : $this->year,
847            $this->month % $this->calendar->monthsInYear() + 1,
848        ];
849    }
850
851    /**
852     * Get today’s date in the current calendar.
853     *
854     * @return int[]
855     */
856    public function todayYmd(): array
857    {
858        return $this->calendar->jdToYmd(Carbon::now()->julianDay());
859    }
860
861    /**
862     * Convert to today’s date.
863     *
864     * @return AbstractCalendarDate
865     */
866    public function today(): AbstractCalendarDate
867    {
868        $tmp        = clone $this;
869        $ymd        = $tmp->todayYmd();
870        $tmp->year  = $ymd[0];
871        $tmp->month = $ymd[1];
872        $tmp->day   = $ymd[2];
873        $tmp->setJdFromYmd();
874
875        return $tmp;
876    }
877
878    /**
879     * Create a URL that links this date to the WT calendar
880     *
881     * @param string $date_format
882     * @param Tree   $tree
883     *
884     * @return string
885     */
886    public function calendarUrl(string $date_format, Tree $tree): string
887    {
888        if ($this->day !== 0 && strpbrk($date_format, 'dDj')) {
889            // If the format includes a day, and the date also includes a day, then use the day view
890            $view = 'day';
891        } elseif ($this->month !== 0 && strpbrk($date_format, 'FMmn')) {
892            // If the format includes a month, and the date also includes a month, then use the month view
893            $view = 'month';
894        } else {
895            // Use the year view
896            $view = 'year';
897        }
898
899        return route(CalendarPage::class, [
900            'cal'   => $this->calendar->gedcomCalendarEscape(),
901            'year'  => $this->formatGedcomYear(),
902            'month' => $this->formatGedcomMonth(),
903            'day'   => $this->formatGedcomDay(),
904            'view'  => $view,
905            'tree'  => $tree->name(),
906        ]);
907    }
908}
909