@edgarblythe,
We've "Thanksgiving" (
Erntedank) earlier here in Germany - in the Catholic church on the first Sunday in October, in the Protestant churches on the first Sunday after Michaelmas (29 September).
In the past, it was customary to celebrate the end of the harvest with a big feast. Lords of the manor and farmers thanked everyone who had helped with the harvest with harvest festivals. As a reward for their hard work, the harvesters, maids and farmhands were treated to a feast and harvest beer, music was played and there was much celebration.
Nowadays, the harvest festival is an opportunity to show children and adults the value of our food and to explain that bread, fruit and vegetables do not grow in supermarkets and how much work is involved from sowing to harvesting.
The Christian core of the harvest festival is not only giving thanks but also sharing. That is why the food from the harvest altar is donated to the needy, homeless shelters or other institutions. There is also an appeal for donations for aid projects.