In case anyone out there wanted more proof that iTunes for Windows is a nasty, spiteful applications, take a look at this issue that's cropped up in the latest release:
Hi, today's update perfectly until I found out that the dates in may calendar are all shifted by ONE day. This is uncanny, how the heck can this happen? I'm on PC, Outlook etc. Contacts are ok btw. Yes I rebooted, re-sync'ed and even selected "the" one calendar I have and also selected to overwrite the iPhone calendar which BTW I deleted manually in a painstaking job, I'm out of ideas. Any light bulbs over you head?
It's a confirmed problem, and so far there doesn't seem to be a fix from Apple. If you rely on syncing Outlook with your iPhone, you might want to give the latest release a miss (alternatively you can mess about with syncing via Google Calendar, which seems to be one workaround).