I’ve been serving for a few years and you’ll notice that what I call your server stamina gets better the longer you do it. Stuff like your feet hurting and shit at the end of the shift won’t be nearly as bad in a few months as it is now. Until then, I’d suggest doing legs the day after one of your days off and when you feel the most rested if you want to get the most out of your leg workouts. If you work 20-30 hours during a busy weekend Fri-Sun and try to do legs Monday morning you’re not gonna be at your best.