Or Heilige Drei Könige, as it's known over here.
There's quite a cool tradition associated with this.
The "Sternsinger" - Star Singers, after the star that the Magi followed - are kids from the local parish who go from house to house by invitation and sing, recite a poem or say a prayer and then mark the lintel or the door with C+M+B and the year with consecrated chalk.
Which stands for both Christus mansionem benedicat - Christ, bless this house - and Caspar, Melchior and Balthasar, the Magi .
Oder Cool, nicht wahr?
Ou Cool, n'est pas?
Disclaimer: I know it's out of season, but I didn't want to wait another 7 months...