If you are a regular annual pass holder for Universal Studios Tours, there are certain blackout dates when you cannot visit the park unless you pay for a one day full priced ticket for the blackout date. Not being aware of these dates may cause you problems, so make sure you know when they are!
In 2006, there are no blackout dates during the months of January through June, and no blackout dates in October. Every Saturday and Sunday are blacked out for July and August. Additionally, July 3rd and 4th are blackout dates. September 2nd and 3rd, November 24th and 25th, and December 26th, 27th, 28th, 29th, 30th, and 31st are all blacked out.
Additionally, the park is closed on Thanksgiving Day and Christmas Day. If you are a regular annual pass holder, either upgrade to a premium or deluxe annual pass, or avoid the Universal Studios Tours on these dates so that you will not have to pay the full one day price which costs almost as much as a regular annual ticket!