Am running WW V5.6.53 with Vista theme on both Vista SP2 x64 Business and Windows 7 RC Build 7100.
In the Daily 10-day display, the change to the next day is always ~ 3 hours, 20 minutes late. This occurs every day. If I go to Weather.com and check the 10-day info, the previous day info is not showing after 12:00 midnight. I have observed this continuously because I am typically online as midnight rolls through my USA EDT time zone. The previous day drops off around 3:20 a.m.