.BR mktime ()
should (use timezone information and system databases to)
attempt to determine whether DST is in effect at the specified time.
-
+.PP
The
.BR mktime ()
function modifies the fields of the
.BR mktime ()
also sets the external variable \fItzname\fP with
information about the current timezone.
-
+.PP
If the specified broken-down
time cannot be represented as calendar time (seconds since the Epoch),
.BR mktime ()
.BR localtime ()
return a pointer to a
.IR "struct\ tm" .
-
+.PP
On success,
.BR gmtime_r ()
and
.BR localtime_r ()
return the address of the structure pointed to by
.IR result .
-
+.PP
On success,
.BR asctime ()
and
.BR ctime ()
return a pointer to a string.
-
+.PP
On success,
.BR asctime_r ()
and
.BR ctime_r ()
return a pointer to the string pointed to by
.IR buf .
-
+.PP
On success,
.BR mktime ()
returns the calendar time (seconds since the Epoch),
expressed as a value of type
.IR time_t .
-
+.PP
On error,
.BR mktime ()
returns the value
and
.BR localtime_r (),
are specified by SUSv2.
-
+.PP
POSIX.1-2001 says:
"The
.BR asctime (),
was set before including
.IR <time.h> .
This is a BSD extension, present in 4.3BSD-Reno.
-
+.PP
According to POSIX.1-2004,
.BR localtime ()
is required to behave as though