We reported earlier that the first known case of Sasser.E was reported roughly 10 hours after the arrest of the author. After this several users have contacted us and reported seeing the worm even before that.
The arrest was done in Germany on Friday the 7th of May 2004 at 13:00 GMT (14:00 German time).
The earliest report of spotting Sasser.E we now know of was 3 hours and 45 minutes later, on Friday the 7th of May 2004 at 16:45 GMT (this was in east coast USA, with infection coming from Sweden).
However, since Sasser spreads really fast, there must be even earlier spottings...or Sasser.E was not released by the apprehended virus writer (Mr. "SJ").