After Saturn-Day comes Sun-Day, a day named after our local star. (To clarify: I’m referring to the nearby ball of hot, flaming gas, not a regional celebrity.) ((To clarify the clarification: I’m also not referring to any politician, but to the astronomical object.)) [And by ‘astronomical’ I mean ‘in space’ not ‘really, really big’ (although in this case both apply). And by ‘space’ I mean ‘outer,’ not the stuff in your attic.]
I trust things are perfectly clear now. It’s Sunday, so we worship the sun. Or in many cases, the Son. It may be a sacred day—a Sabbath day—or it may be just a day off from (normal) work. [For some parts of the world, it’s just a regular work day.]
A very common view is that Sunday afternoon is just for fun.