The official simultaneous worldwide launch of
Overwatch is tomorrow, but
that is as early as this afternoon in some territories.
This post on Battle.net
has the details on when to expect the release, which will be at 7:00 pm EDT,
saying: "Similar to the Open Beta, Overwatch will launch in all gameplay regions
across all platforms at the same time globally. To find out when Overwatch will
be available in your region, check out the reference guide below."