How (if at all) do your sims celebrate the holidays in their calendar?

My sims don't celebrate any holidays at this point. I delete every one of the default holidays. They will celebrate holidays at some point, but it will be ones I choose and on my schedule. I play with aging off so even though the game advances the seasons at a set pace, the years and the schedule of events moves at my pace. In my saves a single year may have dozens of springs, summers, etc. Or they may have only one. It's all down to the story and whatever fits the narrative at a given moment. Time is fluid.