app/Date/JulianDate.php
<?php
/**
* webtrees: online genealogy
* Copyright (C) 2023 webtrees development team
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
declare(strict_types=1);
namespace Fisharebest\Webtrees\Date;
use Fisharebest\ExtCalendar\JulianCalendar;
use Fisharebest\Webtrees\I18N;
/**
* Definitions for proleptic Julian dates.
*/
class JulianDate extends AbstractGregorianJulianDate
{
// GEDCOM calendar escape
public const ESCAPE = '@#DJULIAN@';
// For dates recorded in new-style/old-style format, e.g. 2 FEB 1743/44
private bool $new_old_style = false;
/**
* Create a date from either:
* a Julian day number
* day/month/year strings from a GEDCOM date
* another CalendarDate object
*
* @param array<string>|int|AbstractCalendarDate $date
*/
public function __construct($date)
{
$this->calendar = new JulianCalendar();
parent::__construct($date);
}
/**
* Most years are 1 more than the previous, but not always (e.g. 1BC->1AD)
*
* @param int $year
*
* @return int
*/
protected function nextYear(int $year): int
{
if ($year === -1) {
return 1;
}
return $year + 1;
}
/**
* Process new-style/old-style years and years BC
*
* @param string $year
*
* @return int
*/
protected function extractYear(string $year): int
{
if (preg_match('/^(\d\d\d\d)\/\d{1,4}$/', $year, $match)) {
// Assume the first year is correct
$this->new_old_style = true;
return (int) $match[1] + 1;
}
if (preg_match('/^(\d+) B\.C\.$/', $year, $match)) {
return -(int) $match[1];
}
return (int) $year;
}
/**
* Generate the %Y format for a date.
*
* @return string
*/
protected function formatLongYear(): string
{
if ($this->year < 0) {
return /* I18N: BCE=Before the Common Era, for Julian years < 0. See https://en.wikipedia.org/wiki/Common_Era */
I18N::translate('%s BCE', I18N::digits(-$this->year));
}
if ($this->new_old_style) {
return I18N::translate('%s CE', I18N::digits(sprintf('%d/%02d', $this->year - 1, $this->year % 100)));
}
/* I18N: CE=Common Era, for Julian years > 0. See https://en.wikipedia.org/wiki/Common_Era */
return I18N::translate('%s CE', I18N::digits($this->year));
}
/**
* Generate the %E format for a date.
*
* @return string
*/
protected function formatGedcomYear(): string
{
if ($this->year < 0) {
return sprintf('%04d B.C.', -$this->year);
}
if ($this->new_old_style) {
return sprintf('%04d/%02d', $this->year - 1, $this->year % 100);
}
return sprintf('%04d', $this->year);
}
}