Understanding Lunar and Solar Calendars
The way humanity measures time is categorized into the Solar Calendar, based on the Sun's movement, and the Lunar Calendar, based on the Moon's phases.
1. Solar Calendar
Defines a year by the time it takes for Earth to orbit the Sun (approx. 365.2422 days). The Gregorian Calendar is the global standard, offering a consistent correlation between dates and seasons.
2. Lunar Calendar
Defines a month by the cycle of the Moon's phases (approx. 29.5306 days). 12 lunar months total about 354 days, which is roughly 11 days shorter than the solar year.
💡 What is a Leap Month (Intercalation)?
Because the lunar year is 11 days shorter, lunar dates would eventually drift away from the seasons without correction. To fix this, a Leap Month is added roughly every three years.
- Normal Month: The standard 12 months of the year.
- Leap Month: An extra month inserted to align the calendar with the seasons.
3. Why use a converter?
- Traditional Holidays: Lunar New Year (Seollal) and Chuseok follow the lunar calendar.
- Ancestral Rites: Many birthdays and memorial services are still observed using lunar dates.
- East Asian Astrology: Traditional systems like Saju use lunar dates and Gapja information to determine fortune.
What is "Ganji(干支)"?
The terms like 'Year of the Wood Snake' or 'Earth Rat Month' shown in the results represent the "Ganji (Sexagenary Cycle)". This system combines 10 Celestial Stems and 12 Earthly Branches to record years, months, and days, and is the basis for the 12 zodiac animals.
Ganji vs. Gapja
"Ganji" is the general term for the Stem-Branch system. "Gapja" specifically refers to the first pair in the cycle, though it is often used as a synonym for the entire system in colloquial Korean.