As always with anything Blizzard, the time zones tend to confuse people. Especially with people who live and work overseas from NA.
I found this time zone converter so that people can see EXACTLY the time when the game will be ready to go in their area.
For instance, I live in the eastern half of Canada, and I am on EDT. So I add 3 hours to the launch time of midnight. 12:01 AM PDT is 3:01 AM EDT
For those who have huge time differences like the almost 24 hour differences in Australia, New Zealand etc, it will actually be 5 PM Tuesday in Sydney before you can play.
So use this thing, and see exactly when you get your game!!