Example 1: I live in the United Kingdom and the time here is 13.32 GMT 0, the server's GMT is +1 so I only add 1 hour on my clock.
Example 2: I live in China and the GMT here is +8, I need to be on the server at 18:00 (Server GMT +1) I go forward 7 hours, GMT +2 19:00
GMT +3 20:00
GMT +4 21:00
GMT +5 22:00
GMT +6 23:00
GMT +7 00:00
GMT +8 01:00 - I need login at 01:00 China time.