What the Heck is Tibb's Eve?

It's a tradition in Newfoundland to celebrate Tibb's Eve (some call it Tipp's Eve or Tipsy Eve) on the 23rd of December, to really officially kick off the Christmas Season. I've noticed that in other parts of Canada, at least in recent years, the Christmas Season seems to last the month (or two) leading up to December 25, and then Christmas is abruptly forgotten on the 26th. Back when I was