I'm not too strict about it, but I do try to keep an eye on the calendar for the week ahead. If my sim is dying to take a day off, but Summer Vacation is coming up in a few days, I'll hold out for that (and make sure they get a good night's sleep the night before so I can start their vacation early in the morning with their needs filled). Or if I'm trying to get a child or teen's grades up, I might make them power through to finish homework during the week, but if it's Friday, they can take it easy and revisit the homework on Sunday. Or if I'm planning to have my sim ask someone out on a date, and that free evening out is coming up, I might sometimes have them wait for the free meals.