almanarkASTRONOMICAL CALENDAR
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Xiaoshu (Minor Heat)

Xiaoshu is the moment the Sun reaches 105° 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.

Xiaoshu in 2020–2035

YearInstant (UTC+8) Day
2020 2020-07-06 23:14:28 Mon
2021 2021-07-07 05:05:29 Wed
2022 2022-07-07 10:38:01 Thu
2023 2023-07-07 16:30:41 Fri
2024 2024-07-06 22:20:03 Sat
2025 2025-07-07 04:04:59 Mon
2026 2026-07-07 09:56:57 Tue
2027 2027-07-07 15:37:03 Wed
2028 2028-07-06 21:30:18 Thu
2029 2029-07-07 03:22:23 Sat
2030 2030-07-07 08:55:29 Sun
2031 2031-07-07 14:48:51 Mon
2032 2032-07-06 20:40:54 Tue
2033 2033-07-07 02:24:57 Thu
2034 2034-07-07 08:17:39 Fri
2035 2035-07-07 14:01:11 Sat

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 Xiaoshu about 5 hours 49 minutes later each year until a leap day pulls it back. That is the whole reason Xiaoshu 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