While being a non-believer (but raised in a Catholic family, when not working or shopping during Sunday was strictly observed), I still consider it "an ancient

While being a non-believer (but raised in a Catholic family, when not working or shopping during Sunday was strictly observed), I still consider it "an ancient wisdom". I am trying to have one day of rest (i.e. intended not working, not to confuse with "I wanted to work, but it turned out that I was slacking off"), but given that I always have some overdue projects, it's too tempting not to "observe Sabbath". However, I see that in the long run it's better to rest one day (and doing programming side projects is not rest in that sense) rather than have 7 days of reduced productivity.