@TS1299 I have no rules for when I switch between households, and my aging is off, so I don't need to keep a structure for seasons. But having them set to 28 days gives enough time to play a few households during each, if I want to; and I switch to the ones that have some sort of important relation to a particular season, like gardeners, when that season arrives, and during winter I switch to the city folk and the party goers.. for instance.
I have deleted all the premade holidays and made my own. Not all holidays are celebrated by all my sims; and so I switch household to the ones that do when that holiday approaches. The game gives a notification one day before.