public static function jdToGregorian($julian_day)
    {
        // PHP has different limits on 32 and 64 bit systems.
        $MAX_JD = PHP_INT_SIZE == 4 ? 536838866 : 2305843009213661906;

        return self::jdToCalendar(self::$gregorian_calendar, $julian_day, 1, $MAX_JD);
    }