I started running my allnighters from 11pm to 6am. My reasons were based on my own experiences at other events. For example, I noticed that most people were leaving early, and at some nighters, they were empty by 5am. Also, they were very quiet in the early hours. ie. 8pm to 11pm.......I was talked into starting at at 10pm, and use that hour to give people a chance to dj and showcase what they have to offer.......
The fact is, that we are all getting to the stage when we can't go out all weekend, and stay up all night. Especially when we are travelling 2/3/4/ even 5 hours to get to venues.....I'm happy with 10pm to 6am. And even then it can be dead the last hour.....
12pm to 8am sounds fantastic, but in reallity you would struggle to find a venue that would go along with those hours. And I think it would be dead for the last couple of hours......
Just m.h.o. of course.
Phil.