US release date is approx 11 hours from now, here it is for different time zones. Remember even if you are outside US you can unlock early by doing the VPN trick - see the borderlands 2 pc performance thread on gaf for more info about this.

BORDERLANDS 2 US RELEASE TIMES

EST - 12:00am
PST - 9:00pm
BST (UK) - 5:00am
GMT - 4:00am
CEST - 6:00am
CDT - 11:00pm

Steam pre-load went up yesterday, if you haven't already done so you can pre-download the game ready for release day (18th for US and 21st for EU).

This just saves you some time come release day and allows you to jump in as soon as the game unlocks.