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Mangzhong (Grain in Ear)

Mangzhong is the moment the Sun reaches 75° of apparent ecliptic longitude. It is one of the twelve "Jie" — the BaZi month pillar turns to the month at this instant, and the governing month changes with it.

Mangzhong in 2020–2035

YearInstant (UTC+8) Day
2020 2020-06-05 12:58:26 Fri
2021 2021-06-05 18:52:06 Sat
2022 2022-06-06 00:25:49 Mon
2023 2023-06-06 06:18:21 Tue
2024 2024-06-05 12:09:54 Wed
2025 2025-06-05 17:56:32 Thu
2026 2026-06-05 23:48:21 Fri
2027 2027-06-06 05:25:48 Sun
2028 2028-06-05 11:16:00 Mon
2029 2029-06-05 17:09:58 Tue
2030 2030-06-05 22:44:30 Wed
2031 2031-06-06 04:35:42 Fri
2032 2032-06-05 10:27:59 Sat
2033 2033-06-05 16:13:27 Sun
2034 2034-06-05 22:06:41 Mon
2035 2035-06-06 03:50:50 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 Mangzhong about 5 hours 49 minutes later each year until a leap day pulls it back. That is the whole reason Mangzhong 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