holidays disappeared

@Mysyn1Hello!  Since you've already tried repairing and deleting cache files, I wonder if those holidays were permanently deleted somehow.  Are you seeing other holidays or events?  The premade holidays, like Harvestfest and Winterfest, as well as those you create are the only ones that will display in the calendar ahead of time.  The random holidays like Rebate Day and New Skill Day don't display until you're in the week / season in which they're scheduled.  The only premade events that display all the time are the Finchwick Fairs from Cottage Living.  Other random events like the festivals from City Living also only appear on the week / season they are scheduled.

If you are seeing the other holidays and events, perhaps you could just recreate the events on the calendar manually.  These are the settings for Harvestfest and Winterfest if you don't remember all the traditions.

When i create a new holiday manually, it doesn't show up? 

I just noticed that this has happened to me too, but when I added a holiday manually it appeared.
I also have found an issue where I have had holidays that I've removed, like Brawl Day and Talk Like a Pirate Day from this save in the past mysteriously return and had removed them again. Now I'm beginning to wonder if it's connected to that somehow and they were actually the missing main holidays (Winterfest, Harvestfest, Love Day and New Year's Eve), but with the wrong pictures on them for some reason.