is this 5 hits in an absolute 24 hour period (i.e. 11:00 am march 26 to 11:00 am March 27)
or is it 5 hits in a day (5 hits from 12:00 am march 26 to 11:59 march 26, then another five hits from 1200 am to 11:59 pm on the 27th)?

If it's absolute, wouldn't you really have to wait more than 24 hours to hit again, just to make sure you didn't overlap?

Just asking for clarification.

11 am to 11 am. Probably would have to wait 10-15 minutes before you attack. Use that time to build up another ship or missle for your fleet, but unless you are at war, there is no point in attacking 5 times unless they have large profit to be gained.

viewtopic.php?f=8&t=951 -A forum topic explaining why

Bashing
It is not allowed to attack any given planet or moon owned by a player over 5 times in a single 24 hours period. - In another topic in general discussion called "Bashing Rule"