how to store user timezone in database code example

Example 1: set database timezone mysql

SET GLOBAL time_zone = '+8:00';
SET GLOBAL time_zone = 'Europe/Helsinki';
SET @@global.time_zone = '+00:00';

Example 2: database timezone

the list of database timezone can be found in the link below

https://en.wikipedia.org/wiki/List_of_tz_database_time_zones