Just a quick thought, why not have Four big tournaments a year, each to accomidate a season? You know, a Winter Tournament, Spring Tournament, Summer Tournament, Fall Tournament...
Considering some of us are in school and some have vacation around the same time (since we come from different countries we most likley don't all have similiar vacations around similar times) so it would be easy if you're free for that week to schedule for a tournament. Whadaya think? Plus it would be a nice theme as well.