Of course we shouldn't limit good deeds to one day a week, but I am a pretty sure that most of us could take care of all our business 6 days a week and leave sunday to being sunday.
For most of the people I know, that's not practical at all.
That is funny, because for most people I know, that is how they do things. and I bet the people I know are not necessarily any richer or poorer or busier or more overbooked, etc, than the people you know.
I bet we know the same kind of people.
Bringing it back to what I said before that you make time for the things you want to do.