24 Solar Terms
Computes the year’s 24 solar terms to the minute of 절입시각, with the 삼복 dates and which term today falls in.
The 24 절기 are not fixed dates: each is the moment the sun reaches a particular ecliptic longitude, so 입춘 falls on the 3rd or the 4th depending on the year and the 절입시각 can be minutes either side of midnight. This computes them for a chosen year, to the minute, in Korean Standard Time.
Now
Last term
입동 (立冬)
11/7 · 3 days ago
Next term
소설 (小雪)
11/22 · in 12 days
The start of winter, and traditionally the marker for preparing 김장.
The 24 terms, by year
| Term | Date | Entry time | Longitude | Meaning |
|---|---|---|---|---|
| 소한小寒 | 1/5 (Mon) | 17:23 | 285° | Lesser cold — in practice the coldest stretch of the year. |
| 대한大寒major | 1/20 (Tue) | 10:45 | 300° | Greater cold. After this term comes 입춘 again. |
| 입춘立春 | 2/4 (Wed) | 05:02 | 315° | The start of spring, and the point at which the year turns in 사주. |
| 우수雨水major | 2/19 (Thu) | 00:52 | 330° | Rain water: the snow melts into rain and the ice breaks up. |
| 경칩驚蟄 | 3/5 (Thu) | 22:59 | 345° | Insects that slept through the winter wake up. |
| 춘분春分major | 3/20 (Fri) | 23:46 | 0° | The spring equinox. Day and night are equal, and the days grow longer from here. |
| 청명淸明 | 4/5 (Sun) | 03:40 | 15° | Clear and bright. It falls a day either side of 한식. |
| 곡우穀雨major | 4/20 (Mon) | 10:39 | 30° | Grain rain: the spring rain that brings on the crops. |
| 입하立夏 | 5/5 (Tue) | 20:49 | 45° | The start of summer. |
| 소만小滿major | 5/21 (Thu) | 09:37 | 60° | Sunlight grows plentiful and things begin to fill out. |
| 망종芒種 | 6/6 (Sat) | 00:48 | 75° | Time to sow the bearded grains. |
| 하지夏至major | 6/21 (Sun) | 17:24 | 90° | The summer solstice, the longest day; the sun reaches the Tropic of Cancer. |
| 소서小暑 | 7/7 (Tue) | 10:57 | 105° | Lesser heat. The real heat begins. |
| 대서大暑major | 7/23 (Thu) | 04:13 | 120° | Greater heat. The monsoon ends and the hottest days arrive. |
| 입추立秋 | 8/7 (Fri) | 20:43 | 135° | The start of autumn. Still hot, but the night wind changes. |
| 처서處暑major | 8/23 (Sun) | 11:19 | 150° | The heat withdraws — the day, as the saying has it, that bends a mosquito’s mouth. |
| 백로白露 | 9/7 (Mon) | 23:41 | 165° | White dew begins to settle on the grass. |
| 추분秋分major | 9/23 (Wed) | 09:05 | 180° | The autumn equinox. Day and night are equal, and the nights grow longer from here. |
| 한로寒露 | 10/8 (Thu) | 15:29 | 195° | Cold dew. |
| 상강霜降major | 10/23 (Fri) | 18:38 | 210° | Frost begins to fall. |
| 입동立冬 | 11/7 (Sat) | 18:52 | 225° | The start of winter, and traditionally the marker for preparing 김장. |
| 소설小雪major | 11/22 (Sun) | 16:23 | 240° | Lesser snow: the first snow. |
| 대설大雪 | 12/7 (Mon) | 11:52 | 255° | Greater snow. |
| 동지冬至major | 12/22 (Tue) | 05:50 | 270° | The winter solstice, the longest night. It fixes the eleventh lunar month, and 팥죽 is eaten. |
삼복 — the three dog days
초복 (first)
7/15
Wed
중복 (middle)
7/25
Sat
말복 (last)
8/14
Fri
중복 → 말복
20 days
a 월복 year
초복 and 중복 are the third and fourth 경(庚) day after the summer solstice, 말복 the first after 입추. That is why some years leave twenty days between 중복 and 말복 — a 월복(越伏) year.
A term is defined as the *instant* the sun’s apparent longitude reaches the next multiple of 15°, not as a date. When that instant falls close to midnight, calendars can disagree by a day.
This table is computed in Korean standard time (UTC+9) and agrees to the minute with the times published by the Korea Astronomy and Space Science Institute. The same solar position is used by the lunar calendar converter and the zodiac and 사주 tool.
How to use it
Choose the year
All 24 terms are listed with the date and the 절입시각, plus which term today falls in.
Use the time, not just the date, at a boundary
A 사주 reckoned from 입춘, or a term that begins at 23:40, turns on the minute. That is the reason the time is shown rather than only the day.
Look up 삼복 separately
초복, 중복 and 말복 are counted from 하지 and 입추 by a rule of their own rather than being solar terms, which is why 중복 and 말복 are sometimes twenty days apart instead of ten.
Common questions
Do these match the official Korean figures?
They match the 절입시각 published by 한국천문연구원 to the minute, computed in Korean Standard Time (UTC+9). A different time zone gives a different local date for a term that falls near midnight.
Why is 입춘 sometimes the 3rd and sometimes the 4th?
Because the solar year is not a whole number of days. The instant drifts about six hours later each year and jumps back a day at each leap year, so the calendar date moves within a two-day window.
Are the solar terms the lunar calendar?
No — the opposite. The terms are defined by the sun’s position and are therefore solar; they are used inside the lunisolar calendar to decide which month is a leap month, but the terms themselves have nothing to do with the moon.
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