A repetitive dive is any dive that occurs before off-gassing of nitrogen has completed. This time will vary depending on the dive, and the dive table used. US Navy Dive tables give a maximum length of time for this to occur as 12 hours, while NAUI dive tables put it at 24 hours. Under PADI tables you only have 6 hours to off gas completely. When in doubt being conservative does not hurt but pushing the boundaries certainly can.

For comparison purposes, a side-by-side exam will easily show U.S.Navy Dive Tables to be the 'safest', or most conservative, giving the longest decompression /out gas times, next safest are the (sadly) now-defunct NAUI tables, which are only slightly less 'safe', or conservative, while the resort/hotel/rental industry-sponsored PADI 'tables' are simply designed to let a diver belt down a couple more beer on the 'safety' boat before diving again.

Well that's it buddy.