dysize(3) -- Linux man page
NAMEdysize - get number of days for a given year
#define _BSD_SOURCE /* or: #define _SVID_SOURCE */
int dysize(int year);
DESCRIPTIONThe function returns 365 for a normal year and 366 for a leap year. The calculation for leap year is based on:
(year) %4 == 0 && ((year) %100 != 0 || (year) %400 == 0)
The formula is defined in the macro __isleap(year) also found in <time.h>.
CONFORMING TOThis function occurs in SunOS 4.x.
NOTESThis is a compatibility function only. Don't use it in new programs. The SCO version of this function had a year-2000 problem.
SEE ALSOstrftime(3), time(3)