When is the holiday season.

The holiday starts with Thanksgiving. It continues into December with college students taking Winter Break plus Christmas vacations. It ends 1 or 2 weeks after New Year's.

Well, there's no technical holiday season. But the rest of the Year I'd say requires flexibility. If one major airport (like BWI, DC or NY) gets snowed in, it affects all flights. And it's a highly traveled time between now and Jan 2nd.