We have created Live Clocks app which is simple and easy to use world clock application & widget.
Configure settings on AdminCP
Support 3 clocks
Mutilpe timezone by offset
Automatic Daylight Saving Time conversion on affected timezones
Multiple clock skins support (5 skins with index from 1 to 5)
To find specific GMT offsets, goto: http://www.timeanddate.com/time/zone/. Search "location" and use "Current Offset". If location is currently observing DST, add 1 to offset
And more features to improve Request your custom feature at firstname.lastname@example.org.