When I had a team, we'd trade based on faith -- Jewish or Muslim folks worked Christmas, and on their holidays us "cultural Catholics"[1] covered so they could have "their" day off.

Even among those who were no longer religious, folks often had families who still hold these beliefs.

(I was educated in a Catholic school, was an altar boy, and will never return to either place, so I use the term "cultural Catholicism" to distinguish my agnosticism from the full blown atheism I see on HN which often has a bit too right libertarian branding for my left libertarian tastes.)