An interesting subject, and one reason why I have asked to go on to part time working later this year. A recent room comment started as a joke went on to more serious discussion - should the over-50s not have to do night duties? I.e. should they be rostered for days instead? I'm 56 and the few nights which I do (I can usually get spinners) completely knacker me for nearly a week.... and it gets seriously worse as the years ago by. I'm sure the young people will throw out the idea but they might learn, in time, that it has some merit.
As for working on days off - that's for the birds. You only have to say "No".