What happened on January 6 ?

Ancient Latvia - Zvaigznes Diena observed

Christianity (except Eastern and Oriental Orthodox who follow the Julian Calendar) - Epiphany of the Lord (a.k.a. "Twelfth Day of Christmas" and Three Kings Day in some areas).

Epiphany (National Holiday) in Italy

In the Irish Calendar- Little Christmas or Nollaig na mBan (Women's Christmas) and/or Twelfth Day.

Rastafari movement - Celebration of the ceremonial birthday of Haile Selassie

Armenian Christmas (except in the Holy Land where it's on January 18th - old calendar)

Twelfth Night, or The Lord of Misrule