(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
cal_to_jd — Converts from a supported calendar to Julian Day Count
cal_to_jd() calculates the Julian day count for a date in the specified calendar. Supported calendars are CAL_GREGORIAN, CAL_JULIAN, CAL_JEWISH and CAL_FRENCH.
calendarCalendar to convert from, one of CAL_GREGORIAN, CAL_JULIAN, CAL_JEWISH or CAL_FRENCH.
monthThe month as a number, the valid range depends on the calendar
dayThe day as a number, the valid range depends on the calendar
yearThe year as a number, the valid range depends on the calendar
A Julian Day number.