Question

I need to convert a date and time (GMT) into a timestamp with php. The following code shows what I’m currently using:

<?php
$date="2012-06-29 10:50";
$timestamp = strtotime($date);
echo $timestamp;
?>

However, when I test the timestamp in an online convertor (http://www.epochconverter.com), the resulting date is 29th June 2012, 8:50 GMT, or 2 hours previous. Is it possible that the strtotime() function isn’t completely accurate and is just an estimate of the time? If so, are there better methods I could use for getting the exact time?

Thanks.

Answer 1

strtotime assumes that you are converting a string in your server’s local time, so if the servers time zone is two hours out the result will be as wll.

The comments in the manual suggest a couple of solutions, you can append UTC to your date:

$timestamp = strtotime($date.' UTC');

Or you can change the default timezone for the script (this will apply to all other time functions!):

date_default_timezone_set('UTC');
$timestamp = strtotime($date);

As a final alternative, you could try date_create_from_format which allows you to specify what exactly the format your string is:

$datetime = date_create_from_format('Y-m-d H:i', $date, new DateTimeZone('UTC'));

$timestamp = date_format($datetime, 'U');
// Alternatively (thanks Herbert) - 5.3+ only
$timestamp = date_timestamp_get($datetime);