Question

Here’s a simple version of the table users:

+--------------+-------------------+
|      id      |     timezone      |
+--------------+-------------------+
|       1      | 'Europe/Helsinki' |
|       2      |  'Europe/Paris'   |
+--------------+-------------------+

I want to know what’s the local time for each one of these users (depending on their time zones), so that I can select users for who it’s 4pm for example.

I’m using the LAMP stack, but I’d like to do that using MySQL only (not selecting all users and running them in a PHP loop).

Answer 1

Use the CONVERT_TZ for this:
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_convert-tz

SELECT * FROM users WHERE hour(CONVERT_TZ(now(), server_tz, `timezone`))=16