Anyone have any suggestions on a program to shift the time/date info on pictures?

I have a bunch of pics that I would like to change the time info due to time zone difference.

I recently uploaded a bunch of pics to Flickr and they have a "time shift" feature that you can change the time/date info forward or backward by X hours to compensate for time zone differences.

Is there a good program to do this on the pics on my computer?

I am running Windows (Vista right now, don't know if I'll keep it) by the way.

From what I understand, there is "EXIF" info attached to pics where the info is stored. Is that the info that would need to be changed?

Also, any suggestions for a good program to sort through pics? I have tried "Picasa" from Google, and it is okay, but any other suggestions?