Rocky Horror Picture Show - How Long Is the Time Warp?
At the part of the movie when Magenta and Riff Raff are singing the beginning of the Time Warp the clock shows 6:00 (and rings seven times). After the Time Warp they are going onto the elevator and if you listen the clock rings 10 times. No wonder everyone collapses after, they danced for 4 hours!
Frank has altered the time. Or perhaps it was Riff Raff. If you watch the collectors edition, they said that the aliens did not know about human items, hence, the clocks were probably wrong, because, superior beings that they are, they probably don't need clocks. I don't think that they were dancing for that long! Also, Rocky says at the end that he is "just seven hours old," so the whole time they were in the house could not have been very long.