I bet if you were able to view participation figures there would be a bit of a jump in numbers around that time. I think a lot of people see the first couple of days @ Augusta and get the urge to go and play themselves (Even if that urge does wear off after 9 holes, 60 shots and 16 Pinnacle golds!!)
For our club it's the first weekend of April. That is the first medal played off the white tees and the start of the summer order of merit events. Also it's the Captains Drive in.
If all goes to form should be wet, cold and windy!!!