Guild Wars 2 Headstart Access is less than three days away for players who pre-purchased, and less than five for those who pre-ordered. So this afternoon, mass emails were sent out to the community, announcing exactly when early access begins for both crowds.
If you pre-purchased Guild Wars 2 (fully paid off), then you'll gain access to the game on Saturday, August 25, soon as the clock strikes midnight. As always, that's in Pacific time, since ArenaNet is situated on the West Coast. In an effort to prevent a potential clusterfluff, ArenaNet may actually bring the servers up three hours before then.
For the people who pre-ordered, you'll be getting one day of Headstart time, which begins at midnight on August 27. Yeah, that'd be Sunday night/Monday morning, so not the best time. Keep in mind that pre-order code registrations have been enabled.
Be sure to check account management on the Guild Wars 2 site to download and install the client ahead of time.