Chinese lunar calendar converter: Gregorian to lunar dates, 1901-2100

How the Chinese calendar works

The Chinese calendar is lunisolar. Each month starts on the day of the new moon, counted in Beijing time (UTC+8), and has 29 or 30 days. Twelve months make 353 to 355 days, so about every third year gets a 13th month to keep the calendar in step with the seasons.

The rules are set by the national standard GB/T 33661-2017, drafted by the Purple Mountain Observatory. The month that contains the winter solstice is always month 11. The year begins at the second new moon after that month, or the third when a leap month comes between, so Chinese New Year falls between 21 January and 20 February.

Lunar years in the converter are labelled by the Gregorian year in which they begin. The lunar year 2026 runs from 17 February 2026 to 5 February 2027.

How to read a lunar date

A lunar date is written as month and day in Chinese numerals. 九月十四 means the 14th day of the 9th month, which is 23 October 2026, and 九月初三, the 3rd day of the same month, is 12 October 2026. The first month is 正月, the 11th is 冬月 and the 12th is 腊月. Days 1 to 10 take the prefix 初, and days 21 to 29 use 廿 for twenty.

The same lunar date falls on a different Gregorian date every year. The 15th day of the 8th month, the Mid-Autumn Festival, was 25 September 2026 and is 15 September 2027. Lunar birthdays work the same way: convert the lunar month and day for each year you need.

Leap months and solar terms

The year is divided into 24 solar terms (节气), points about 15 days apart on the sun’s yearly path. Twelve of them are principal terms (中气), and the winter solstice (冬至) is one. In a 13-month span between two winter solstices, the first month without a principal term becomes the leap month.

A leap month repeats the number of the month before it and is marked 闰. Recent and coming cases:

• 2025: a leap 6th month from 25 July 2025
• 2026 and 2027: no leap month
• 2028: a leap 5th month from 23 June 2028
• 2033: a leap 11th month from 22 December 2033, a rare case

Solar terms in 2026 include 立春 (Start of Spring) on 4 February, 春分 (spring equinox) on 20 March, 清明 on 5 April and 冬至 on 22 December. On 23 October 2026 the term is 霜降, Frost’s Descent.

Chinese New Year 2026 to 2030

The year name comes from the sexagenary cycle (干支). Ten heavenly stems (甲乙丙丁戊己庚辛壬癸) pair with twelve earthly branches (子丑寅卯辰巳午未申酉戌亥), and the pairs repeat every 60 years. The branch gives the zodiac animal and the stem gives the element, so 丙午 is a Fire Horse year, as was 1966.

The converter changes the animal at Chinese New Year, not on 1 January. Someone born on 10 February 2026 was born in a Snake year (乙巳), because the Horse year had not yet begun. Some traditions change the animal at 立春 instead, about 4 February.

Where our data comes from

Our month table for 1901 to 2100 is generated from the open-source lunar-javascript library and checked day by day against the Hong Kong Observatory’s conversion tables. All days match except one month in 2057, when the new moon falls within minutes of Beijing midnight and published sources disagree. We follow the Observatory and start that 9th month on 28 September 2057.

Do not rely on the Chinese calendar in the date functions built into web browsers (the ICU library). It differs from the Hong Kong Observatory in 12 months between 1901 and 2100, including Chinese New Year 2027 and 2030, which it shows a day off. The Chinese calendar 2026 and Chinese calendar 2027 pages list every day, and How we calculate gives the details.

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