DYSIZE(3) Linux Programmers Manual DYSIZE(3)
dysize - get number of days for a given year
int dysize(int year);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
dysize(): _BSD_SOURCE || _SVID_SOURCE
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
This function occurs in SunOS 4.x.
This is a compatibility function only. Dont use it in new programs.
The SCO version of this function had a year-2000 problem.
This page is part of release 3.05 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2007-07-26 DYSIZE(3)