Both the United States and Canada have Thanksgiving holidays, though they are different. Both are located on the continent of North America, but you can't really say the whole North America celebrates the same holiday.
Only America and Canada celebrate thanksgiving as it is a holiday were they celebrate the day that they Pilgrims came to America and celebrated by having a feast with some Native Americans. So only America and Canada celebrate thanksgiving.
Canada celebrates Thanksgiving in October on the second Monday.
Canada and the United StatesCanada celebrates Thanksgiving on the third Monday in October and the United States celebrates Thanksgiving on the fourth Thursday in November.
Thanksgiving
China
Do you mean "when"? If so, Canadians celebrate Thanksgiving during early October.
Thanksgiving has no religious significance and no one religion.
Thanksgiving Day traditionally celebrates the arrival of the first pilgrims to America.
There is no such thing. Only the USA celebrates thanksgiving as a national event.
6 at the most
I'll answer when you correct your grammar.
Israel
Canada