Chinese Lunar Calendar
The traditional Chinese lunisolar calendar — moon phases define months, solar terms define the year.
What is the Chinese lunar calendar?
The Chinese lunar calendar (农历 / 阴历) is a lunisolar calendar — it tracks both the Moon's phases and the Sun's position. Months start at the new moon (朔), and each month is 29 or 30 days, depending on when the next new moon falls. A normal lunar year has 353–355 days, roughly 11 days shorter than a solar year.
To keep the calendar aligned with the seasons, a leap month (闰月) is added about every three years. This is why Chinese New Year falls on a different solar date each year — usually somewhere between January 21 and February 20.
Solar terms (二十四节气)
The 24 solar terms (节气) divide the solar year into 24 equal segments, each marking a point in the Sun's apparent path along the ecliptic. They are the backbone of the agricultural calendar and were used by farmers to decide when to plant and harvest.
Each term lasts about 15 days. The two most important are Spring Equinox (春分) andAutumn Equinox (秋分), when day and night are equal length. Summer Solstice (夏至) is the longest day, and Winter Solstice (冬至) is the shortest.
Heavenly Stems & Earthly Branches (天干地支)
The calendar also uses a 60-day cycle formed by combining 10 Heavenly Stems (天干) with 12 Earthly Branches (地支). Each year, month, day and hour has its own stem-branch pair. This is the system behind the Chinese zodiac and the 60-year "jiazi" (甲子) cycle.
Is the lunar calendar still used today?
Yes — while China officially uses the Gregorian calendar for daily life, the lunar calendar still governs traditional festivals: Chinese New Year, Mid-Autumn Festival, Dragon Boat Festival, and Qingming Festival are all based on the lunar calendar. The lunar calendar is also used for choosing auspicious dates, fortune-telling, and in traditional Chinese medicine.
Astronomical calculations follow the official standards published by thePurple Mountain Observatory (紫金山天文台).