If you are a routine yearly pass holder for Universal Studios Tours, there are specific blackout dates when you can not check out the park unless you spend for a one day complete priced ticket for the blackout date. Not knowing these dates might trigger you issues, so make certain you understand when they are!
In 2006, there are no blackout dates throughout the months of January through June, and no blackout dates in October. Furthermore, July 3rd and 4th are blackout dates.
Furthermore, the park is closed on Thanksgiving Day and Christmas Day. If you are a routine yearly pass holder, either upgrade to a premium or luxurious yearly pass, or prevent the Universal Studios Tours on these dates so that you will not need to pay the complete one day cost which costs practically as much as a routine yearly ticket!