I've seen a few questions about this but not a clear answer... strtotime() will use the default timezone set for PHP when converting the string to a unix timestamp.
However, I want to convert a string to unix timestamp in UTC. Since there is no parameter for doing so, how can this be done?
The string I'm trying to convert is: 2011-10-27T20:23:39, which is already in UTC. I want to represent that as a unix timestamp also in UTC.
Thank you
I realize this question is very old, but I found another option that can be helpful. Instead of setting and then reverting php's time zone, you can specify the timezone as a part of the string you pass to strtotime like so:
echo date_default_timezone_get(); output: America/Chicago echo gmdate('Y-m-d H:i:s', strtotime('2011-10-27T20:23:39')); output: 2011-10-28 01:23:39 echo gmdate('Y-m-d H:i:s', strtotime('2011-10-27T20:23:39 America/Chicago')); output: 2011-10-28 01:23:39 echo gmdate('Y-m-d H:i:s', strtotime('2011-10-27T20:23:39 UTC')); output 2011-10-27 20:23:39 Note: I am on PHP 5.5.9, but this should work in any php version.
Set the system default timezone before making the strtotime call:
date_default_timezone_set('UTC'); echo strtotime('2011-10-27T20:23:39')."\n"; // Proof: print_r(getdate(strtotime('2011-10-27T20:23:39'))); // IMPORTANT: It's possible that you will want to // restore the previous system timezone value here. // It would need to have been saved with // date_default_timezone_get(). Both other answers are really fine. As I have the same issue, I want to offer a third option.
$utc = new DateTimeZone('UTC'); $dt = new DateTime('2011-10-27T20:23:39', $utc); var_dump($dt->format('U')); gives string(10) "1319747019"
new DateTimeZone('UTC');, see stackoverflow.com/a/34651091/1066234