
It will depend on when the entries closed because until you know the entry you can't decide on the ring order. You need to try as far as possible that all rings finish at about the same time to eliminate too much hanging around and empty rings, mind you some show societies are not very good at this and one wonders if the idea has even crossed their minds.
Any way back to the running order once the entries are all in about a week after the closing the show secretary can get round to working out what goes into each ring and when so it may be only a week before a show when the information becomes available.