I overheard a conversation recently:
A Person: Monday is the Canadian Thanksgiving
Another Person: Why do they need another Thanksgiving?

I was already aware that Canada’s Thanksgiving was on a different date from the States and had always assumed that it was because Canuck harvest season is earlier than the US one. That was just a guess though so I looked it up in Wikipedia (Thanksgiving (Canada)).

Martin Frobisher gets credit for celebrating the first Canadian Thanksgiving in 1578. I’d never heard of Martin despite having spent grades 6 through 13 within Ontario’s school system.

Thanksgiving days occurred off and on with various pretexts throughout the seventeen and eighteen hundreds on various dates, sometimes Spring, sometimes Fall. In 1957, Parliament fixed Thanksgiving to the second Monday of October.

Fun fact: Americans pronounce Canadian Thanksgiving as “Columbus Day”.