The 24 Solar Terms — Exact Times Table

The 24 solar terms (節氣, jiéqì) divide the Sun's apparent path along the ecliptic into 24 equal arcs of 15 degrees each, measured from the spring equinox at ecliptic longitude 0°. 立春 (Start of Spring) sits at 315°, the summer solstice at 90°, the winter solstice at 270° — each term corresponds to a precise astronomical instant, which is exactly what this table lists.

A common misconception is that solar terms belong to the lunar side of the Chinese calendar. It is the opposite: they are defined purely by the Sun's position, independent of the Moon. That is why their Gregorian dates are nearly fixed — 清明 (Qingming) always falls on April 4 or 5, the winter solstice on December 21 or 22 — while their dates on the lunar calendar drift every year. Solar terms are the solar component of the Chinese lunisolar calendar: months follow the Moon, but leap-month placement is governed by the terms.

The 24 terms split into two alternating groups: twelve 節 (jié, "section" terms — 立春, 驚蟄, 清明, 立夏, 芒種, 小暑, 立秋, 白露, 寒露, 立冬, 大雪, 小寒) and twelve 中氣 (zhōngqì, "mid-point" terms — 雨水, 春分, 穀雨, 小滿, 夏至, 大暑, 處暑, 秋分, 霜降, 小雪, 冬至, 大寒). The 節 terms mark month boundaries for BaZi; the 中氣 terms govern lunar-month naming — a lunar month without a 中氣 becomes a leap month. Both roles are explained below.

Historically there were two ways to compute the terms. The "mean term" method (平氣) simply divides the year into 24 equal spans of about 15.22 days — simple, but it ignores the fact that Earth's orbital speed is not constant: Earth moves faster near perihelion (early January) and slower near aphelion (early July), so the Sun's apparent motion runs fast in winter and slow in summer.

The "true term" method (定氣) instead defines each term by the Sun's actual position: 立春 occurs at the very instant the Sun reaches ecliptic longitude 315°. The Shíxiàn calendar of 1645 adopted true terms officially, and they have been used ever since. Under true terms, the gaps between adjacent terms are unequal — about 14.7 days in winter and 15.7 days in summer — which is why term dates wobble within a day or two and the exact times differ every year.

This table uses the true-term method, computing astronomically the exact instant the Sun's apparent longitude reaches each multiple of 15°, expressed in UTC+8 — the standard reference meridian of the official calendar.

For most everyday purposes, knowing the day of a term is enough. Not for BaZi. The BaZi month pillar is bounded not by lunar months but by the transition instants of the twelve 節 terms: the 寅 month begins at the moment of 立春, the 卯 month at 驚蟄, and so on. The year pillar likewise switches at the instant of 立春 — not at Lunar New Year.

This means that for someone born on a transition day, being born before or after the exact moment changes the month pillar entirely (and on 立春 day, the year pillar too). If 小暑 transitions at 05:57 in some year, a baby born at 4 a.m. that day still belongs to the 午 month, while one born at 7 a.m. belongs to the 未 month — three hours apart, one full pillar of difference. This is the first thing a traditional chart reader checks in the almanac.

That is exactly why this table lists every term to the minute: if you (or the person you are charting) were born on a term day, look up the exact time here first, then decide which month applies. Our free BaZi chart tool builds this check in — it compares the birth moment against the transition instant automatically.

A side note: only the twelve 節 terms bound months; the twelve 中氣 terms (equinoxes, solstices and the rest) do not switch the month pillar — but they govern leap-month placement in the lunar calendar, and the equinoxes and solstices also open the four cardinal signs of Western astrology (Aries, Cancer, Libra, Capricorn). East and West anchor their calendars on the same astronomical events.

The terms arose in the agricultural society of the Yellow River basin, and their names sketch a year of farming and phenology: 驚蟄 is spring thunder waking hibernating insects, 芒種 the time to sow bearded grains, 霜降 the arrival of first frost. Even where local climate differs from the terms' northern origins, they remain embedded in everyday customs across the Chinese-speaking world: tomb-sweeping at 清明, tangyuan dumplings at the winter solstice, nourishing meals at 立冬.

The terms live on in proverbs and food wisdom that use them as anchors of the year. In 2016, the 24 solar terms were inscribed on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity — sometimes dubbed "China's fifth great invention".

The transition times in this table are computed astronomically from the Sun's apparent longitude using the true-term method, expressed in UTC+8 and listed to the minute. Lookups cover the current year plus or minus two years — we only serve the range where the algorithm is reliable in the modern epoch. We do not store your query (the year) or use it for any other purpose.

Honest note: times published by different institutions can differ by a few minutes, owing to differences in solar-position model precision (e.g. how nutation and aberration are handled). This is normal and almost never affects the date itself. If your use case requires officially certified times, defer to the almanac of your national astronomical authority. Our computation methods and engine details are public on our methodology page: /methodology.