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.
month
The month as a number, the valid range depends
on the calendar
day
The day as a number, the valid range depends
on the calendar
year
The year as a number, the valid range depends
on the calendar