Almost every aspect of traditional Korean life was also based on the lunar calendar. Koreans divided each year into twelve months, beginning with the winter solstice. Twenty-four solar subdivisions (cholgi) corresponded to the days on which the sun entered the first and fifteenth degrees of the twelve zodiacal signs.

Koreans traditionally used an almanac to divine the workings of the universe and nature. The almanac also served as a guide for changes in the seasons and corresponding customs and practices. The following is a brief introduction to the twenty four seasonal subdivisions which traditional Koreans used as indices in their daily lives. While the Gregorian calendar is the official calendar today, the lunar calendar and the almanac based on it are still influential in rural Korea.