So while we use the names interchangeably when we speak English, Germans actually traditionally distinguish between Santa Clause/Saint Nicholas and Father Christmas.
Father Christmas comes on Christmas Eve, visiting each house with children and asking them for poems and Christmas carols in exchange for the presents.
["When we all believe" by Rose O'Neill]
However, in the night from the 5th to the 6th of December, that's when Santa Clause comes visiting!
Instead of leaving presents under the tree (which may not even have been put up yet at this point), he puts some small gifts into the clean shoes of children. Many children actually clean their shoes with their parents on the 5th of December so gifts will be left in them.
It's an incredibly cute tradition when families grow up. My Mom and I often spend this time together, so we end up playing a really silly game of trying to sneak around each other to leave little gifts in each other's shoes at night!
Sometimes, I forget because we're busy, and wake up to find my shoes like this.
Mama has never forgotten about it even once. ♡