38  * month. This assumes the internal date representation, where a year
50 typedef struct date date;  typedef
54 static date jiswitch = {1582, 7, 3};
56 static date	*date2idt(date *idt, date *dt);
57 static date	*idt2date(date *dt, date *idt);
58 static int	 ndaysji(date *idt);
59 static int	 ndaysgi(date *idt);
63  * Compute the Julian date from the number of days elapsed since
66 date *
67 jdate(int ndays, date *dt)  in jdate()
69 	date    idt;		/* Internal date representation */  in jdate()
95 	/* return external representation of the date */  in jdate()
101  * The date is given according to Julian calendar.
104 ndaysj(date *dt)  in ndaysj()
106 	date    idt;		/* Internal date representation */  in ndaysj()
115  * Same as above, where the Julian date is given in internal notation.
119 ndaysji(date * idt)  in ndaysji()
126  * Compute the date according to the Gregorian calendar from the number of
127  * days since March 1st, year zero. The date computed will be Julian if it
130 date   *
131 gdate(int ndays, date *dt)  in gdate()
134 	date    idt;		/* for internal date representation */  in gdate()
173 	/* return external representation of found date */  in gdate()
178  * Return the number of days since March 1st of the year zero. The date is
183 ndaysg(date *dt)  in ndaysg()
185 	date    idt;		/* Internal date representation */  in ndaysg()
193  * Same as above, but with the Gregorian date given in internal
197 ndaysgi(date *idt)  in ndaysgi()
238 	date    dt;  in week()
251 	date idt;  in firstweek()
275 	date dmondaygi = {1997, 8, 16}; /* Internal repr. of 1997-11-17 */  in weekday()
291  * Convert a date to internal date representation: The year starts on
295 static date *
296 date2idt(date *idt, date *dt)  in date2idt()
314 static date *
315 idt2date(date *dt, date *idt)  in idt2date()