Question

I have users from all around the world using our system. Each of them has chosen their local timezone (recorded as UTC e.g. UM8 etc)

All of our data is saved using UTC as the standard so all data can be compared.

I can show the date/time local to the user using codeigniter’s gmt_to_local() function ( http://codeigniter.com/user_guide/helpers/date_helper.html ) but it asks for DST = True/False.

How can i look up the Timezone to see if it is observing DST currently?

Answer 1

And addition to Corbin’s answer (+1 to him):

If you had real timezone name, then you could use the code like

$date = new DateTime('now', new DateTimeZone('Pacific/Auckland'));
echo $date->format('I'); // 0

$date = new DateTime('now', new DateTimeZone('Europe/London'));
echo $date->format('I'); // 1

Which means that in Auckland (New Zealand) it is not a DST, and in London it is