FUNCTION c_grejul(year, month, day, jdate)
long *year; long *month; long *day; long *jdate;
The year.
The number of the month, where January = 1 and December = 12.
The day number of the month.
The Julian date in the given year. The Julian date is the numerical position of the date in the year, starting with January 1 at 1 and ending with December 31 at 365 (or 366 in a leap year).
The Gregorian date (month and day) of the given year is converted to a Julian date.
c_grejul() is located in the file julian.c.
c_grejul() has no return value.