[wideawake]

It's not actually "Thank- Penance- and Bed" day, but a day of Thanksgiving, Penance and Prayer. In Swiss German the word "Bett" (prayer) is homonymic with the word for "bed" in High German.

It is a Protestant holiday which began as a way to telescope the Catholic holidays of the Name of Mary, the Exaltation of the Holy Cross and others into one day.

[0beron]

I looked it up. It’s actually non-sectarian at least in Switzerland, and I thought the Bett- referred to the great plague of 1639. Sorry for the confusion.

Here’s the article:

http://de.wikipedia.org/wiki/Eidgen%C3%B6ssischer_Dank-,_Buss-_und_Bettag