Why is Canadian Thanksgiving and American Thanksgiving on different days?

They just are.

https://www.cnn.com/2019/10/07/world/canadian-thanksgiving-2019-trnd/index.html

They celebrate a concept and not a specific calendar-date event. Any nation could set a day of gratitude whenever they want.

Happy Thanksgiving, Canadian guy.

It’s so certain lucky people can get twice as much turkey and pumpkin pie.

I also suspect that our northerly neighbor might find late November a dicier time for family travel.

Most likely, just a result of weather. It’s a harvest festival, after all, and early October is more in line with the farming experiences for Canadians, while much of the US is warmer, longer.

Because they are two different countries.

Canadian Thanksgiving pre-dates US Thanksgiving by almost 50 years, and celebrates Frobisher’s thanksgiving in Newfoundland, which was held in October. In 1578, English explorer Martin Frobisher and his crew gave thanks and communion was observed, either on land at Frobisher Bay,

US Thanksgiving is tied to the Pilgrims’ thanksgiving feast at Plymouth in 1621, which is why it is celebrated in November.

One has nothing to do with the other.

@zenvelo True regarding Frobisher, but American Thanksgiving became a national holiday nearly a century before its Canadian counterpart did in 1879, according to the Canadian Encyclopedia.