Hmm... I think that the best time for such contest can be 6:00 or 20:00 GMT.
If it will be 6:00 GMT, then:
7:00 UK
9:00 Latvia, Norway, Ukraine
Good time in Russia
18:00 New Zealand
23:00 California
If it will be 20:00 GMT, then:
8:00 New Zealand
13:00 California
21:00 UK
23:00 Latvia, Norway, Ukraine
Late time in Russia
Correct me if I'm wrong
I think that the best day is Saturday or Sunday - holidays. What do you think abut this dudes, what time do you prefer?