I have run into the same issue and here is what I did to resolve it:
In /wp/wp-includes/functions.php
Add the following before the first function:
date_default_timezone_set(‘America/New_York‘);
Not sure if this is the best place to put this but some of the other places I tried it didn't work or only worked for certain parts of WordPress
via WordPress › Support » Php 5.3.0 & WP 2.8 (It is not safe to rely on the system’s timezone).