I always feel guilty when I have my best financial ideas on a Sunday and I start trying to act on them, because I keep thinking that I shouldn’t be working on the sabbath (sometimes I wonder if I’m Jewish, since I don’t do much on Saturday either). My view is that if you have ideas on Sunday, and you are trying to “relax” that is the reason you are having the idea (i.e. your brain is no longer obsessing about the day to day, and is attempting to think about other things, and thus your subconscious is now doing stuff for you).
Sunday (or whatever day is your Sabbath), should be a day of rest, but not a day of inaction.