3.2. Converting Time and Date Parts to an Epoch Timestamp
Problem
You want to know what epoch timestamp corresponds to a set of time and date parts.
Solution
Use mktime( )
if your time and date parts are in
the local time zone:
// 7:45:03 PM on March 10, 1975, local time $then = mktime(19,45,3,3,10,1975);
Use gmmktime( )
if your time and date parts are in
GMT:
// 7:45:03 PM on March 10, 1975, in GMT $then = gmmktime(19,45,3,3,10,1975);
Pass no arguments to get the current date and time in the local or UTC time zone:
$now = mktime(); $now_utc = gmmktime();
Discussion
The functions mktime( )
and gmmktime( )
each take a date and time’s parts (hour,
minute, second, month, day, year, DST flag) and return the
appropriate Unix epoch timestamp. The components are treated as local
time by mktime( )
, while gmmktime( )
treats them as a date and time in UTC. For both
functions, a seventh argument, the DST
flag (1 if DST is being observed, 0 if not), is optional. These
functions return sensible results only for times within the epoch.
Most systems store epoch timestamps in a 32-bit signed integer, so
“within the epoch” means between
8:45:51 P.M. December 13, 1901 UTC and 3:14:07 A.M. January 19, 2038
UTC.
In the following example, $stamp_now
is the epoch
timestamp when mktime( )
is called and
$stamp_future
is the epoch timestamp for 3:25 P.M.
on June 4, 2012:
$stamp_now = mktime( ); $stamp_future = mktime(15,25,0,6,4,2012); print $stamp_now; print $stamp_future; 1028782421 1338837900
Both epoch ...
Get PHP Cookbook now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.