I have a tactic for working on weekends to make it less painful.
This is it: I jog in.
This accomplishes three things:
A. I am smelly, dirty and haven't taken a shower. Therefore, the day hasn't REALLY started yet. Days start with showers and if I don't take one until late, well, my day is just short. Yes, I am that simple.
B. People who are also working realize I actually AM sort of "dressed up" every other day of the week. Even if it just looks like jeans and a cotton shirt.
C. I got exercising out of the way, and therefore feel superior to all the other losers that are also working on the weekend. I get to say..."oh, yeah (like I completely forgot I stink and look terrible) I jogged in today" and behave as if I do it all the time.
You can try it too, but I don't recommend it for jobs where you actually have to look nice (waitressing, retail, banking, modeling, teaching, medicine, librarian, etc) or for jobs where work is work (landscaping, arboriculture, track coach, mason, plumber etc). I think that might just leave scientists and the homeless, but I wouldn't recommend it for them either, they need to conserve their energy.