What's on December 6th?
In most parts of Belgium, The Netherlands and the north of France we celebrate "Sinterklaas" aka "Saint-Nicolas Day".
It is a festive day for children, they find gifts in the morning as Saint-Nicolas rides the rooftops in the night of the 5th to the 6th and his compagnon/aid "Zwarte Piet" ("Black Pete") climbs through the chimneys to bring toys & gifts to kids who behaved good the past year.
As a thanks for past gifts and/or to make sure the Saint will show up again on their roof, on the evening of 5th December kids put
shoes in front of the fireplace with carrots in them for Saint-Nicolas´ dunkey (or horse, depending on different versions of the tale).
Playmobil released some very cool exclusive Saint-Nicolas sets a few years ago for the Benelux countries (BElgium-NEtherlands-LUXembourg).
"Santa" in the USA is most probably another interpretation of the centuries-old Saint-Nicolas tale, of which many divergent versions exist all over Western-Europe. By influence from overseas (USA), we now more & more celebrate "Santa" as well, while before Christmas was more celebrated as a kind of purely religious & family feast without (much) (toy)gifts & all the commercial stuff.