uppesittarkväll

Noun

 * 1) an evening where one stays up late doing a certain thing (usually with family)
 * 2) December 23 (to prepare for Christmas, celebrated on December 24)
 * 3)  a television or radio event broadcast on December 23 and running into the evening; a pre-Christmas special

Usage notes
Often specifically of the Bingolotto pre-Christmas special.