Reference · 24 terms · 12 sectional, 12 mid

The 24 solar terms

The Chinese calendar is usually called lunar, and that is half right in a way that hides the interesting half. Its months follow the moon. Its year follows the sun, and it does so through 24 marks called solar terms, spaced 15 degrees apart around the sun's apparent path through the sky. Each opens a stretch of about a fortnight and carries a name: Rain Water, Awakening of Insects, Grain in Ear, Frost's Descent. Together they are the reason a lunisolar calendar stays in step with the seasons instead of wandering out of them.

One thing to get straight before the table, because it is the commonest confusion about this system: the big Chinese festivals are not solar terms. A solar term is a point on the sun's path, so it lands on nearly the same western date every year. A festival like the Mid-Autumn Festival is fixed to a lunar date instead, which is why it can swing almost a month against the western calendar while the equinox beside it does not move. Qingming is the single crossover, and it gets its own answer at the bottom of this page.

Four of them a Western reader already owns. Spring Equinox, Summer Solstice, Autumn Equinox, Winter Solstice sit at 0, 90, 180, 270 degrees, which is to say the two equinoxes and the two solstices, the same four moments any almanac marks. The Chinese system takes that circle and puts in twenty more marks. This page gives all 24 with their dates, then explains the two jobs they do that nothing else in the calendar can.

All 24, with dates

Listed from Li Chun, the term the astrological year opens on, so the last two fall in January of the following year. Dates are computed from the shared calendar engine and are reckoned in China Standard Time, which can shift a term by a day for readers further west.

Term	Sun	2026	2027	2028	What it marks
1. Start of Spring lì chūn · 立春	315°	Feb 4	Feb 4	Feb 4	The year opens. Nothing has thawed yet, and that is the point: the term marks the turn rather than the weather.
2. Rain Water yǔ shuǐ · 雨水	330°	Feb 18	Feb 19	Feb 19	Precipitation stops arriving as snow and starts arriving as rain. The first observable confirmation that the turn was real.
3. Awakening of Insects jīng zhé · 惊蛰	345°	Mar 5	Mar 6	Mar 5	Thunder is said to wake the hibernating creatures. The most vivid name in the set, and pure folk explanation rather than entomology.
4. Spring Equinox chūn fēn · 春分	0°	Mar 20	Mar 21	Mar 20	Day and night equal. One of the four terms Western calendars also mark, and the zero point of the whole circle.
5. Pure Brightness qīng míng · 清明	15°	Apr 5	Apr 5	Apr 4	The only solar term that is also a public holiday, when families sweep the graves. Air clear, ground workable, ancestors visited.
6. Grain Rain gǔ yǔ · 谷雨	30°	Apr 20	Apr 20	Apr 19	The rains that seedlings need. Names in this stretch stop describing the sky and start describing the crop.
7. Start of Summer lì xià · 立夏	45°	May 5	May 6	May 5	The second of the four "start" terms, which fall roughly midway between a solstice and an equinox rather than on either.
8. Grain Buds xiǎo mǎn · 小满	60°	May 21	May 21	May 20	The grain is filling but not yet full. Small fullness, which is a more exact agricultural idea than English has a word for.
9. Grain in Ear máng zhòng · 芒种	75°	Jun 5	Jun 6	Jun 5	Awned crops ready to cut, and the next planting due. The busiest fortnight in the farming year.
10. Summer Solstice xià zhì · 夏至	90°	Jun 21	Jun 21	Jun 21	Longest day. The word here means arrival rather than middle: the sun has reached its limit and turns back.
11. Minor Heat xiǎo shǔ · 小暑	105°	Jul 7	Jul 7	Jul 6	Hot but not yet at its worst. The calendar pairs minor and major five times, and always the minor comes first.
12. Major Heat dà shǔ · 大暑	120°	Jul 23	Jul 23	Jul 22	The hottest stretch of the year, arriving a full month after the longest day because ground and water take that long to catch up.
13. Start of Autumn lì qiū · 立秋	135°	Aug 7	Aug 8	Aug 7	Autumn begins while it is still ferociously hot, which sounds wrong and is the clearest sign that these terms track the sun rather than the thermometer.
14. End of Heat chǔ shǔ · 处暑	150°	Aug 23	Aug 23	Aug 22	The heat withdraws. The character means to stop or to dwell, so the name reads as the heat settling down rather than the heat departing.
15. White Dew bái lù · 白露	165°	Sep 7	Sep 8	Sep 7	Dew condenses visibly at dawn. Nights have cooled enough for the air to give up its water, and the year turns audible in the mornings.
16. Autumn Equinox qiū fēn · 秋分	180°	Sep 23	Sep 23	Sep 22	Day and night equal again. From here the nights are longer than the days until spring.
17. Cold Dew hán lù · 寒露	195°	Oct 8	Oct 8	Oct 8	The same dew, now cold to the touch. Two terms one month apart, distinguished by nothing but temperature.
18. Frost's Descent shuāng jiàng · 霜降	210°	Oct 23	Oct 23	Oct 23	First frost. The end of the growing season in the north, and the deadline behind a great deal of autumn work.
19. Start of Winter lì dōng · 立冬	225°	Nov 7	Nov 7	Nov 7	Winter opens. The stored harvest is now the whole economy until spring.
20. Minor Snow xiǎo xuě · 小雪	240°	Nov 22	Nov 22	Nov 22	Snow becomes possible. Like the heat terms, snow is graded in two sizes a fortnight apart.
21. Major Snow dà xuě · 大雪	255°	Dec 7	Dec 7	Dec 6	Heavy snow expected. In the Yellow River basin, where these names were fixed, that was a reliable forecast.
22. Winter Solstice dōng zhì · 冬至	270°	Dec 22	Dec 22	Dec 21	Shortest day. The solstices were the first points anyone could fix with a gnomon, and Chinese astronomical years were reckoned from this one long before the full 24 existed.
23. Minor Cold xiǎo hán · 小寒	285°	Jan 5	Jan 6	Jan 5	The cold deepens after the solstice, for the same lagging reason the heat peaks after midsummer.
24. Major Cold dà hán · 大寒	300°	Jan 20	Jan 20	Jan 20	The coldest fortnight, and the last term of the year. The next one is Li Chun, and the circle closes.

The 2026 column runs from Li Chun 2026 to Major Cold in January 2027, and the other columns likewise.

The geometry, which is simpler than it looks

A solar term is not a date. It is an angle, and the date is what falls out of it. Divide the sun's yearly circuit into 24 equal arcs of 15 degrees and mark the moment the sun crosses each boundary. That is the entire definition, and it explains the property that surprises people most: these dates barely move. Li Chun is February 3, 4 or 5 every year without exception, because the sun reaches 315 degrees when it reaches it, leap years notwithstanding.

Read the angles down the table and the four familiar ones appear on their own, at 0, 90, 180, 270 degrees. Everything between them is Chinese observational work: the fortnight when dew turns white, the fortnight when the grain is filling but not yet full, the fortnight when insects are said to wake. And notice where the four "start" terms fall. Start of Spring is not the equinox and Start of Summer is not the solstice; each sits halfway between one and the next. In this calendar a season is centered on its solstice or equinox rather than beginning there, which is why Start of Autumn arrives in the first week of August, in serious heat, and is not a mistake.

The two jobs the terms do

The 24 alternate between two kinds, and the alternation is not decorative. 12 of them are sectional terms, the odd-numbered ones counting from Li Chun, and 12 are mid terms. Each kind runs a different piece of machinery.

The sectional terms cut the year into twelve months of destiny. Every other calendar month in Chinese astrology begins at a sectional term, not at a new moon and not on the first of anything. Li Chun opens the first month, Awakening of Insects the second, and so on around. This is why a bazi chart's month pillar can disagree with the lunar month a person was born in, and why the astrological year turns in early February rather than at the lunar new year. The full derivation is on our bazi methodology page, and the year boundary itself has a page of its own at Li Chun.

The mid terms decide where the leap month goes, and this is the more elegant of the two. Mid terms are spaced about 30.4 days apart. A lunar month is about 29.5 days. The gap is small, so it takes a while to matter, and then it does: eventually a lunar month begins and ends without any mid term falling inside it. That month is the leap month. In a year with thirteen months, the first month containing no mid term is the one that gets repeated. No table, no fixed schedule, no committee. The calendar detects its own drift and inserts the correction exactly where the drift occurred.

This is the piece that most English explanations skip, and skipping it makes the Chinese calendar look arbitrary when it is the opposite. The moon sets the months. The sun sets the year. The mid terms are the coupling between them, and they do it with one rule.

What the terms are, and are not

They describe one climate. The names were fixed in the Yellow River basin, and they are accurate there and only approximately anywhere else. Major Snow is a reasonable forecast for Henan in December and a joke in Guangzhou. UNESCO's 2016 inscription of the 24 as intangible cultural heritage says as much in its own way: what is being preserved is a body of knowledge developed by watching one sky over one landscape.

They are not a zodiac. A solar term is a fortnight, not a sign, and the tradition does not read a personality off the one you were born in. The place they touch personal reading is the month pillar in bazi, which is a different claim made with different machinery.

They are not divination. The system is calendar astronomy with a farming almanac attached. Its accuracy is the accuracy of the sun's position, which is exact, and the accuracy of a two-thousand-year-old agricultural observation, which is local. Those are two quite different kinds of true, and it is worth keeping them apart.

The one term with a page of its own so far is Li Chun, because it does double duty as the astrological new year. The rest will follow. In the meantime the calendar tools that run on this same engine are the lunar calendar converter and the bazi calculator, both of which resolve these boundaries for a specific date rather than in general.

Common questions

What are the 24 solar terms?

They are 24 fixed points in the solar year, spaced 15 degrees apart around the sun's apparent path, each opening a stretch of roughly a fortnight. They are the solar half of the Chinese lunisolar calendar and they carry the names most people know as seasonal markers, from Start of Spring through the two solstices and equinoxes to Major Cold. Because they follow the sun rather than the moon, each one falls on nearly the same Gregorian date every year.

Are the solar terms part of the lunar calendar?

They sit inside it, but they are not lunar. The Chinese calendar is lunisolar: months follow the moon, and the solar terms keep those months tied to the seasons. Without them the lunar months would drift through the year the way the Islamic calendar does. The terms are the correction that stops it.

Why do the solar term dates barely change from year to year?

Because they are angles, not counts. A term happens at the moment the sun reaches a given ecliptic longitude, so it lands on the same Gregorian date give or take a day, drifting only with the leap-year cycle. Spring Equinox falls at zero degrees, Summer Solstice at 90, Autumn Equinox at 180, and Winter Solstice at 270, which is why those four appear in Western calendars too.

How do the solar terms decide where the leap month goes?

Half of the 24 terms are "mid" terms, spaced about 30.4 days apart, which is slightly longer than a lunar month of about 29.5 days. Sooner or later a lunar month slips through the gap and contains no mid term at all. In a year with 13 months, the first month with no mid term is the leap month. That single rule is what keeps the calendar aligned, and it is why leap months land where they do rather than at a fixed place in the year.

Which solar term starts the Chinese astrological year?

Li Chun, Start of Spring, around February 4. Chinese New Year is the lunar new year and moves between late January and mid February, but bazi and feng shui turn the year at Li Chun instead, which is why a birthday in that gap can be read two different ways.

Is Qingming a solar term or a festival?

Both, and it is the only one of the 24 that is also a public holiday. The term marks the fortnight of clear bright weather in early April; the festival is Tomb Sweeping Day, when families visit and clean the family graves. The holiday takes its date from the term rather than the other way round.

Sources

Solar term, for the 24 names, their solar longitudes, and the sectional and mid classification.
Chinese calendar, for the lunisolar structure and the no-mid-term rule that places the leap month.
UNESCO Representative List, for the 2016 inscription and its description of the terms as knowledge developed by observing the sun's annual motion.
The dates in the table are computed at build time by the same calendar engine that runs this site's converter and bazi tools, so a date here and a date there cannot disagree.