This is an override of the game holiday tradition tunings to make custom traits affecting the Love and Ignoration (Does Not Care) of Holiday Traditions. E.g. Aromantic Sims no longer want to celebrate any love day tradition, Hostile Sims love the fighting tradition, etc.
Now Father Winter arrives at 23:00/11PM, you just have to "Watch" him to complete the tradition about him and your sims now gets moodlets depending on their age.