There is no right or wrong day to prep! Is there any day in the week where you have a pocket of time you can set aside for meal prep? It also doesn't have to be all done at once. You can plan out your meals for the week, and "semi-prep" by washing/chopping all of your veggies, pre cooking grains like rice and quinoa, marinading meats in advance, putting calendar reminders (that's what I do!) to defrost meat/fish the night before so it's ready to cook the next day, etc. On really busy weeks, I recommend picking 2-3 meals that'll last you 2-3 days each so you have leftovers. If you have some time in the evening, you could always cook the next night's dinner before you go to bed (or before you clean up the kitchen from that evening's meal) so you're not rushing to cook dinner at dinnertime. When you meal prep, try to do so in a time-efficient way, such as prepping all of the foods at the same time that require the oven (like roasted veg, cooked meat, casseroles, etc) and doing all of the stovetop meals (like cooked grains, stir fried foods, etc.) at the same time. Hope this helps!