I just imported a blog from Posterous, and all the timestamps are off by about a day. WordPress grabs the Posterous timestamp when it imports, but it does not interpret it correctly. I tried changing my time zone in WP before importing (making sure I permanently deleted the old imported posts first). No difference.
So... Is there any way to shift the timestamps on all posts? I can change them one at a time, but there are dozens of them.
The blog I need help with is dougfertie.wordpress.com.