It goes on all night as far as I know. We've sat down to dinner at the end of one set, and about 20 minutes later they came on again for about 20-30 minutes. I hope this helps.
We went to dinner there around 6:00. We were seated near the end of their show. They took a short break, and were out again before we went back for seconds. I don't think the times posted on the website above is terribly accurate. (JMO) I have eaten there 3 times in the past 10 years, and have always caught the entertainment.
The Steve Soares times are very accurate. When you call to make your ADR, the CM will confirm the time of the show with you. (At least they did for me and I didn't even ask for that info since I already knew.)
These are generally the times and they don't change very often: