How to store users timezone in mysql? [duplicate]

Answer 1

The timezone in one location isn't always the same - for example, the UK is BST (GMT + 1) between March and October. Use one of the timezones supported by PHP:

http://php.net/manual/en/timezones.php

If you do go ahead using numbers, either store them as hours or minutes. Store timezones west of UTC/GMT as negative numbers. For example, the US East Coast would be -5 (hours) or -300 (minutes) - assuming it's 5 hours behind.

Then, add this to the timestamp - the negative or positive will handle the rest.

// for 5 hours behind when stored as hours (-5)
$now = time() + ($offset * 60 * 60);
// for 5 hours behind when stored as minutes (-300)
$now = time() + ($offset * 60);

Answer 2

timezone string would be better than the offset or difference in hours because some timezones are subject of changes

http://www.php.net/manual/en/class.datetime.php

http://www.php.net/manual/en/class.datetimezone.php

for date/time math:

http://www.php.net/manual/en/class.dateinterval.php

http://www.php.net/manual/en/class.dateperiod.php

stop using php functions, oop classes are much better!

Answer 3

Rather than storing it as a string, store it as a number? Then you can simply add that number to the timestamp. (The number can be negative for timezones which would subtract.)