I know that in the USA “Saint Nick” is Santa Claus, but in Romania things are a little different. Saint Nicholas and Santa Claus are two different things.
In Romania, Saint Nicholas (RO: Moș Nicolae) is thought to have helped three poor girls who had nothing to eat or keep themselves warm with, by leaving money at their window at night without anyone knowing.
The tradition says that on the night of the 5th of December, Saint Nicholas comes and leaves gifts (usually fruits and candies) in children’s boots if they’re good and a twig if they’re bad. So children all around Romania clean their boots the night before, make them look shiny, put them at the window and wait for the presents from Saint Nicholas.
Do you have any interesting tradition about Saint Nicholas in your country?