Christmas is celebrated on the 25th December, but presents are usually given
to children on January 1st, St. Basil's Day (Agios Vassilis = Father Christmas).
In Western European countries St. Nicholas is celebrated as a great gift-giver,
and his name is given to Father Christmas, who is supposed to visit children
to give presents at Christmas.
In Greece St Nicholas is the patron saint of sailors, and 6th December is St.
Nicholas Day. In centuries of Greek folklore, Nicholas was seen as "The Lord
of the Sea'. In modern Greece, he is still easily among the most recognisable
saints and December 6 finds many cities celebrating their patron saint. He is
also the patron saint of all of Greece.
In the past there used to be present giving on this day, and boats were
decorated instead of Christmas Trees. The decorated boats are still seen in
some places, but have mainly given way to the western tradition of the
Christmas tree.
http://www.livingincrete.net/christmas.html