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Spring Equinox 春分 · Chunfen

The Spring Equinox 2027 falls on 2027-03-21, Sun, at 04:24:42 UTC+8 — the instant the Sun reaches 0° of apparent ecliptic longitude. It is an astronomical moment, not a day: it happens at the same instant everywhere on Earth, and the local date shifts with your time zone.

The same instant is 春分 (chunfen) in the Chinese solar calendar, where it is one of the twenty-four terms. It is one of the twelve "Qi", which do not move the BaZi month boundary.

The other three cardinal points: Summer Solstice · Autumn Equinox · Winter Solstice

Chunfen in 2020–2035

YearInstant (UTC+8) Day
2020 2020-03-20 11:49:37 Fri
2021 2021-03-20 17:37:28 Sat
2022 2022-03-20 23:33:26 Sun
2023 2023-03-21 05:24:26 Tue
2024 2024-03-20 11:06:25 Wed
2025 2025-03-20 17:01:29 Thu
2026 2026-03-20 22:45:59 Fri
2027 2027-03-21 04:24:42 Sun
2028 2028-03-20 10:17:10 Mon
2029 2029-03-20 16:01:59 Tue
2030 2030-03-20 21:52:07 Wed
2031 2031-03-21 03:40:58 Fri
2032 2032-03-20 09:21:55 Sat
2033 2033-03-20 15:22:45 Sun
2034 2034-03-20 21:17:30 Mon
2035 2035-03-21 03:02:43 Wed

Why it is not the same date every year

A tropical year runs about 365.2422 days while a calendar year is a whole 365 or 366. The leftover quarter-day accumulates, pushing Chunfen about 5 hours 49 minutes later each year until a leap day pulls it back. That is the whole reason Chunfen lands on different dates across 2020–2035 and drifts within roughly a day: the term itself is perfectly regular — every 15° of longitude — and the wobble belongs to the calendar, not the sky.

By term

Sources

  1. lunar-javascript (6tail, MIT) — solar-term instants, 干支 pillars, 大運/流年, 胎元/命宮/身宮 and the almanac tables.
  2. Hong Kong Observatory, Date and Time of the 24 Solar Terms — the reference used to check solar-term instants.
  3. Xieji Bianfang Shu and Sanming Tonghui — classical sources for the Wuhu Dun and Wushu Dun stem rules, hidden stems and the Ten Gods.

Algorithms last checked: 2026-07 · Method and accuracy