Citation:
mktime Convert date/time info to a calendar time.
Synopsis:
mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
The month ("mon"), weekday ("wday"), and yearday ("yday") begin
at zero. I.e. January is 0, not 1; Sunday is 0, not 1; January
1st is 0, not 1. The year ("year") is given in years since
1900. I.e. The year 1995 is 95; the year 2001 is 101. Consult
your system's "mktime()" manpage for details about these and
the other arguments.
Calendar time for December 12, 1995, at 10:30 am.
$time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
print "Date = ", POSIX::ctime($time_t);
Returns "undef" on failure.
En regardant bien l'exemple, tu verras que le jour commence bien par 1 et non 0.