almanarkASTRONOMICAL CALENDAR
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Lidong (Start of Winter)

Lidong is the moment the Sun reaches 225° 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.

Lidong in 2020–2035

YearInstant (UTC+8) Day
2020 2020-11-07 07:13:55 Sat
2021 2021-11-07 12:58:47 Sun
2022 2022-11-07 18:45:30 Mon
2023 2023-11-08 00:35:35 Wed
2024 2024-11-07 06:20:04 Thu
2025 2025-11-07 12:04:04 Fri
2026 2026-11-07 17:52:05 Sat
2027 2027-11-07 23:38:35 Sun
2028 2028-11-07 05:27:16 Tue
2029 2029-11-07 11:16:46 Wed
2030 2030-11-07 17:08:44 Thu
2031 2031-11-07 23:05:40 Fri
2032 2032-11-07 04:54:17 Sun
2033 2033-11-07 10:41:05 Mon
2034 2034-11-07 16:33:40 Tue
2035 2035-11-07 22:23:52 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 Lidong about 5 hours 49 minutes later each year until a leap day pulls it back. That is the whole reason Lidong 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