Today is Thanksgiving. Thanksgiving is one of those mishmash of holidays that has shady and dubious origins from many different traditions.
Tonight I'll talk a little about Thanksgiving in the United States.
Being strict uber-right wing Fundamentalist Christians, the Calvinists of the Massachusetts Bay Colony had many "Days of Thanksgiving" in their calendar. That usually meant they spent all day in Church being all solemn and holy.
The occasion popularly know as "The First Thanksgiving" was simply a Harvest Festivalcelebrating the first successful harvest of the colonists. And certainly there is a lot of giving thanks at a Harvest Feast. After all, you're celebrating the bounty you have grown.