Korea's Lunisolar Calendar
Korea uses a lunisolar calendar (음력, 陰曆) that combines lunar months with solar year corrections. Based on the Chinese astronomical tradition, it was the primary civil calendar in Korea for over a millennium and remains deeply embedded in Korean culture today.
Key Features
- Months begin at the new moon and each month is 29 or 30 days.
- Intercalary months (윤달) are added roughly every 3 years to keep pace with the solar year.
- 24 Solar Terms (절기) — derived from the sun's position — mark agricultural seasons and inform traditional medicine, food culture, and folk customs.
Major Festivals Tied to the Lunar Calendar
- 설날 (Seollal): Lunar New Year on the 1st day of the 1st lunar month. The most important holiday, marked by ancestral rites (차례), family gatherings, and traditional games.
- 정월대보름: The 15th day of the 1st month — the first full moon. Communities share nuts, play traditional games, and burn straw figures to drive away bad luck.
- 추석 (Chuseok): Harvest festival on the 15th day of the 8th month — the year's biggest full moon. Families visit ancestral graves and share foods like 송편 (rice cakes).
- 단오: The 5th day of the 5th month, a summer festival with swings, wrestling, and iris water rituals.
Birthdays and Ancestral Rites
Many Koreans, especially older generations, celebrate birthdays on the lunar date. Ancestral memorial rites (제사) are held on the lunar anniversary of a family member's death. Wedding and moving dates are still often chosen by consulting a traditional almanac (택일).
윤달 — The Lucky Intercalary Month
A 윤달 (intercalary month) has no zodiac or solar term associations, making it considered a "blank" period outside normal cosmic cycles. Traditionally, this made it auspicious for activities normally considered taboo, such as purchasing burial clothes or performing renovations.
Coexistence with the Gregorian Calendar
Since 1896, Korea has officially used the Gregorian calendar for civil purposes. Today, Koreans seamlessly switch between the two systems: work schedules follow the Gregorian calendar, while cultural and family life often references the lunar calendar. Smartphone apps and online converters make the dual-calendar lifestyle effortless.