You know more or less what day of the month a club is opening according to last year's schedule. The line up is quite similar wtih dj's in several months. So go by that if you are booking away. Also, I think that opening is best as it is the most anticipated time. Everyone is refreshed, lot of money in the pocket, new gear just waiting for the clubs to open! Not as crowded as closing although closing is very good too as it wraps up the summer. But in June, it's like the spring of all countires...all the bees come out to play!