Karachun, Korochun or Kračún is a Slavic holiday similar to Halloween as a day when the Black God and other evil spirits are most potent. It was celebrated by pagan Slavs on the longest night of the year, i.e., the night of the winter solstice (December 21).

On this night, Hors, symbolising old sun, becomes smaller as the days become shorter in the Northern Hemisphere, and dies on December 22nd, the winter solstice. It is said to be defeated by the dark and evil powers of the Black God. On December 23rd Hors is resurrected and becomes the new sun, Koleda.

Most scholars have derived this word from the Romanian сrăсiún for Christmas, but a recently discovered Novgorodian manuscript makes the Slavic origin more probable. Max Vasmer derived the word from the Common Slavonic for “to step forward”. In this case, Karachun may be translated as “the day which connects the old year with the new one”. It is opposed to the summer solstice holiday, Ivan Kupala.

Modern scholars tend to associate this holiday with the ancestor worship. On this day, Western Slavs burned fires at cemeteries to keep their loved ones warm, they organized dinings in the honor of the dead so as they would not suffer from hunger. They also lit wooden logs at local crossroads.

In some Slavic languages, the word came to denote unexpected death of a young man and the evil spirit who makes life shorter.