I doubt most will agree, but February 24th.
Why? Because the rumors say retail employees will be trained from 2/9 until 2/16. That same rumor suggests sales start +\-2 weeks later, so my guess for retail launch is March 6th. If it's released on March 6th, that means pre-orders start a week earlier: February 27th. The event would be the Tuesday before that, so... February 24th.