[RESOLVED] Timezone offset and DST

[sidsel]

I got a mysql table with timestamps in UTC. In a user table I got the users offset to UTC. This way I can show the date and time in the users timezone. However when it comes to DST it doesn't work so well.

How do I find out if DST is 0 or 1 for a user? php's date("I") doesn't work as it is relative to the servers location. DST start and end dates differs around the world.

Any ideas?

[Installer]

If you stored the users' timezones instead of fixed offsets, and have a recent-enough php version, you could dynamically get the current offsets like this:

$user_tz = 'America/New_York';

$dt = new DateTime();
$tz = new DateTimeZone($user_tz);
$offset = $tz->getOffset($dt);  // In seconds

[sidsel]

It works fine but the list of timezones is quite long... especially if a user should select his own timezone in a pulldown menu. Would it be possible to list only timezones for a specific country?

There seems to be constant or method called DateTimeZone:😛ER_COUNTRY but I'm not sure how to get it work.