I don't have the high school years pack, it's just random days. Those days happen to be the ones I need to add the holidays to. There isn't anything scheduled on those days either.
@goshinewithflora Does this happen if you let the game finish one 14-day season and move on to the next one? You can just let the game run without saving if you want.
Additionally, if you use mods or custom content, please move the Mods folder to the desktop and delete localthumbcache.package. You don't need to save your progress; this is just for testing. It would however be helpful to let the game change over to a new season.
