The 24 solar terms: dates, pentads and BaZi months
Many people assume the solar terms are part of the lunar calendar. It is the other way round: they are set entirely by the Sun, which is why they land on nearly the same Western calendar dates every year. Farmers used them to time the seasons' work, and BaZi uses them to change the year and the month. In 2016 UNESCO added the twenty-four solar terms to its list of the Intangible Cultural Heritage of Humanity.
Look up the solar terms for any year
Pick a year to list the exact time of all 24 solar terms (Taiwan time, UTC+8) and the month pillar each jie term starts. Add a month and day, such as a birthday, to see which solar-term period it falls in and its month pillar. Everything is calculated in your browser.
The times come from the same calendar code our BaZi charts use; for 1901–2100 they agree with an astronomical calculation to within about a minute. If you were born within minutes of a term changing, see solar term boundaries.
All 24 solar terms
| Solar term | Sun's longitude | Type | Month | 2027 | Pentads |
|---|---|---|---|---|---|
| Start of Spring 立春 | 315° | jie | Yin month starts | Feb 4 09:46 | The east wind thaws the ice; Hibernating insects begin to stir; Fish rise up under the ice |
| Rain Water 雨水 | 330° | middle | Yin month midpoint | Feb 19 05:33 | Otters lay out the fish they catch; Wild geese fly north; Plants begin to sprout |
| Awakening of Insects 驚蟄 | 345° | jie | Mao month starts | Mar 6 03:39 | Peach trees begin to blossom; Orioles sing; Hawks turn into doves |
| Spring Equinox 春分 | 0° | middle | Mao month midpoint | Mar 21 04:24 | Swallows return; Thunder is heard; Lightning first appears |
| Pure Brightness 清明 | 15° | jie | Chen month starts | Apr 5 08:17 | Paulownia trees begin to flower; Field mice turn into quails; Rainbows first appear |
| Grain Rain 穀雨 | 30° | middle | Chen month midpoint | Apr 20 15:17 | Duckweed begins to grow; Turtledoves preen their feathers; Hoopoes alight on the mulberry trees |
| Start of Summer 立夏 | 45° | jie | Si month starts | May 6 01:25 | Mole crickets chirp; Earthworms come out; Snake gourds grow |
| Grain Buds 小滿 | 60° | middle | Si month midpoint | May 21 14:18 | Sow thistle flourishes; Delicate grasses wither; The wheat harvest arrives |
| Grain in Ear 芒種 | 75° | jie | Wu month starts | Jun 6 05:25 | Mantises hatch; Shrikes begin to call; Mockingbirds fall silent |
| Summer Solstice 夏至 | 90° | middle | Wu month midpoint | Jun 21 22:10 | Deer shed their antlers; Cicadas begin to sing; Crow-dipper (Pinellia) sprouts |
| Minor Heat 小暑 | 105° | jie | Wei month starts | Jul 7 15:37 | Warm winds arrive; Crickets shelter by the walls; Young hawks learn to strike |
| Major Heat 大暑 | 120° | middle | Wei month midpoint | Jul 23 09:04 | Fireflies rise from rotting grass; The earth is damp and the heat is sticky; Heavy rains come often |
| Start of Autumn 立秋 | 135° | jie | Shen month starts | Aug 8 01:26 | Cool winds arrive; White dew settles; Autumn cicadas sing |
| End of Heat 處暑 | 150° | middle | Shen month midpoint | Aug 23 16:14 | Hawks lay out their prey; Heaven and earth grow austere; The grain ripens |
| White Dew 白露 | 165° | jie | You month starts | Sep 8 04:28 | Wild geese arrive; Swallows leave; Birds store up food |
| Autumn Equinox 秋分 | 180° | middle | You month midpoint | Sep 23 14:01 | Thunder falls silent; Insects seal their burrows; Waters begin to dry up |
| Cold Dew 寒露 | 195° | jie | Xu month starts | Oct 8 20:17 | Wild geese arrive as guests; Sparrows enter the sea and become clams; Chrysanthemums bloom yellow |
| Frost's Descent 霜降 | 210° | middle | Xu month midpoint | Oct 23 23:32 | Jackals lay out their prey; Leaves yellow and fall; Hibernating insects curl up in their burrows |
| Start of Winter 立冬 | 225° | jie | Hai month starts | Nov 7 23:38 | Water begins to freeze; The ground begins to freeze; Pheasants enter the sea and become giant clams |
| Minor Snow 小雪 | 240° | middle | Hai month midpoint | Nov 22 21:16 | Rainbows hide away; Heaven's qi rises and earth's qi sinks; Everything closes up and winter sets in |
| Major Snow 大雪 | 255° | jie | Zi month starts | Dec 7 16:37 | Night birds fall silent; Tigers begin to mate; Iris shoots push up |
| Winter Solstice 冬至 | 270° | middle | Zi month midpoint | Dec 22 10:42 | Earthworms curl up; Elk shed their antlers; Springs begin to flow |
| Minor Cold 小寒 | 285° | jie | Chou month starts | Jan 5 22:09 | Wild geese turn north; Magpies start to nest; Pheasants call |
| Major Cold 大寒 | 300° | middle | Chou month midpoint | Jan 20 15:29 | Hens begin to brood; Birds of prey fly high and fierce; Ponds freeze solid to the middle |
Times are Taiwan time (UTC+8), computed by the same calendar code as our BaZi charts. Pentads follow the standard Yuan-dynasty list.
Jie and middle terms: one changes the month, one marks its middle
The twenty-four terms come in two kinds that alternate. The twelve jie (節) terms, such as the Start of Spring, Awakening of Insects and Pure Brightness, each open a month. The twelve qi (氣), or middle terms (中氣), such as Rain Water, the Spring Equinox and Grain Rain, fall in the middle of a month.
| Month | Jie term (month starts) | Middle term | Month element |
|---|---|---|---|
| Yin 寅 (≈ 1st lunar month) | Start of Spring | Rain Water | Wood |
| Mao 卯 (≈ 2nd lunar month) | Awakening of Insects | Spring Equinox | Wood |
| Chen 辰 (≈ 3rd lunar month) | Pure Brightness | Grain Rain | Earth |
| Si 巳 (≈ 4th lunar month) | Start of Summer | Grain Buds | Fire |
| Wu 午 (≈ 5th lunar month) | Grain in Ear | Summer Solstice | Fire |
| Wei 未 (≈ 6th lunar month) | Minor Heat | Major Heat | Earth |
| Shen 申 (≈ 7th lunar month) | Start of Autumn | End of Heat | Metal |
| You 酉 (≈ 8th lunar month) | White Dew | Autumn Equinox | Metal |
| Xu 戌 (≈ 9th lunar month) | Cold Dew | Frost's Descent | Earth |
| Hai 亥 (≈ 10th lunar month) | Start of Winter | Minor Snow | Water |
| Zi 子 (≈ 11th lunar month) | Major Snow | Winter Solstice | Water |
| Chou 丑 (≈ 12th lunar month) | Minor Cold | Major Cold | Earth |
The BaZi month pillar only looks at the jie terms: the Mao month begins at the moment of the Awakening of Insects, and the Spring Equinox is just its midpoint. The middle terms do a different job in the lunar calendar: a lunar month that contains no middle term becomes the leap month.
Why BaZi starts the year at the Start of Spring, not Chinese New Year
Both the BaZi year and the BaZi month run on solar terms: the year begins at the Start of Spring, and each month at its jie term. Chinese New Year (the first day of the first lunar month) is set by the Moon and moves between late January and mid-February, often several days away from the Start of Spring. So if you were born between late January and early February, your year pillar depends on the Start of Spring, not on New Year; see solar term boundaries.
Solar terms and astronomy: one every 15°
Over a year the Sun makes one full circle through the stars (the ecliptic, 360°). Starting from the Spring Equinox at longitude 0°, there is a solar term every 15°. Because Earth's orbit is an ellipse, the Sun moves faster in the northern winter, so the winter terms are a little closer together than the summer ones. The four most special terms are the equinoxes and solstices: at the equinoxes day and night are nearly equal; the Summer Solstice has the longest day and the Winter Solstice the shortest. Taipei in 2027:
| Solar term | Sunrise | Sunset | Daylight |
|---|---|---|---|
| Spring Equinox | 05:57 | 18:05 | 12 h 8 min |
| Summer Solstice | 05:04 | 18:46 | 13 h 42 min |
| Autumn Equinox | 05:42 | 17:49 | 12 h 7 min |
| Winter Solstice | 06:34 | 17:09 | 10 h 35 min |
Computed with astronomy-engine (Taipei, standard atmospheric refraction, sunrise and sunset by the Sun's upper edge), local time.
The ancients also read the seasons from the Big Dipper: its handle points east in spring, south in summer, west in autumn and north in winter.
Three common misconceptions
The solar terms are part of the lunar calendar.
They are a solar calendar set by the Sun's position, so their Western calendar dates barely move (the Start of Spring is always February 3–5). The lunar calendar follows the Moon, and its dates wander by weeks. Farmers' almanacs print both side by side, which is where the mix-up comes from.
On the equinoxes, daylight is exactly 12 hours.
The Sun is over the equator on the equinoxes, but atmospheric refraction, plus timing sunrise and sunset by the Sun's upper edge, makes daylight a little longer than 12 hours. At the 2027 Spring Equinox, Taipei gets about 12 h 8 min of daylight.
You can only balance an egg on its end at the Spring Equinox.
With a few small bumps on the shell and a flat enough table, you can stand an egg on any day of the year. It has nothing to do with the solar terms.
The 24 terms one by one
A straight word: solar terms are astronomy; luck is something else
The twenty-four solar terms divide the year by the Sun's position on the ecliptic, and their times can be computed to the second. BaZi uses them to change the year and the month; that is a rule of calculation. A solar term carries no good or bad luck of its own, and no term is a "better" one to be born in: a chart is read as a whole, by its Five Elements and Ten Gods. Everything on this site is for reference and entertainment.
Solar terms set the month; the month sets strength
Your BaZi month pillar comes from the solar terms, and the month element sets the strength of the Five Elements. Enter your birth date for a free Four Pillars chart.
The 24 solar terms: common questions
Are the solar terms part of the lunar or the solar calendar?
The solar calendar. They are set by the Sun's position, which is why their Western calendar dates are almost fixed. The Chinese lunar calendar is lunisolar and follows the Moon. Almanacs print the two together, but the solar terms belong to the solar year.
What order do the 24 solar terms come in?
Start of Spring, Rain Water, Awakening of Insects, Spring Equinox, Pure Brightness, Grain Rain, Start of Summer, Grain Buds, Grain in Ear, Summer Solstice, Minor Heat, Major Heat, Start of Autumn, End of Heat, White Dew, Autumn Equinox, Cold Dew, Frost's Descent, Start of Winter, Minor Snow, Major Snow, Winter Solstice, Minor Cold and Major Cold.
What is the difference between a jie term and a middle term?
There are twelve jie terms (Start of Spring, Awakening of Insects, Pure Brightness…), each opening a month; BaZi changes the month pillar at that moment. The twelve middle terms (Rain Water, Spring Equinox, Grain Rain…) fall mid-month and do not change the month pillar.
Why does BaZi change the year at the Start of Spring?
Because BaZi years and months both run on solar terms: the year starts at the Start of Spring, each month at a jie term. Chinese New Year follows the Moon and is often days away from the Start of Spring, so people born in late January or early February need to check the Start of Spring.