How to convert to UTC

Question

I get dates and times from different sources (for example, file date / time from an FTP server, email date / time, etc.), and you need to store them in UTC format (so everyone has a common link). How can I do it? What parts of the information do I need for the correct conversion.

This is for a PHP web application. So, I can get the time zone of the server. I'm not sure what to do next. Here are some input examples:

• Mon, 28 Jun 2010 12:39:52 +1200
• 2010-06-25 15:33:00

Answer 1

In the first case, the offset exists, so it should be trivial, the second example, however, will be considered as UTC (or any other default time zone). Here is what I suggest:

date_default_timezone_set('UTC'); // set default timezone $one = strtotime('Mon, 28 Jun 2010 12:39:52 +1200'); $two = strtotime('2010-06-25 15:33:00'); // Already UTC? Must be... 

$one and $two will hold timestamps corresponding to the time converted to the UTC time zone.

Answer 2

You can use strtotime() to convert any time format you have into a timestamp, and then use any function, possibly date() , put it in the format in which you want to save everything.