DYSIZE(3) Linux Programmer's Manual DYSIZE(3)

dysize - get number of days for a given year

#include <time.h>
int dysize(int year);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.19:
Glibc 2.19 and earlier:

The 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>.

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
dysize () Thread safety MT-Safe

This function occurs in SunOS 4.x.

This is a compatibility function only. Don't use it in new programs.

2016-03-15 GNU