Similar to KiwiFlyer's date weirdness above,
The dates showing up in post results aren't accurate as to when the post was actually made. I did a search on my username and got these results for the few posts(Sorted in posting date order):
Date reported by search........Actual post date
May 15, 2008 2:34 PM..........May 15, 2008 5:26 pm
May 14, 2008 9:45 PM......... May 14, 2008 4:53 pm
May 15, 2008 2:34 PM......... May 14, 2008 2:42 am
May 15, 2008 11:40 AM....... May 10, 08 1:53 pm