Classical attributes
- Solar position: longitude 90°
- Date range: June 20-22
- Season: summer (middle summer)
- Type: 氣 — Mid-term — within month
- Month branch: 午 (Horse)
Climatic register
The longest day of the year — yang energy at maximum, beyond which it begins to recede. Heat at maximum visibility; from this point, the yin half of the year begins. Traditionally the date when Yin Dun begins in the Qi Men Dun Jia system.
Hidden stems of the 午 month branch
The 午 earthly branch holds these heavenly stems internally — read in BaZi as the “hidden essence” of the month pillar:
- 丁 (Yin Fire, primary)
- 己 (Yin Earth, residual)
BaZi relevance
夏至 is the mid-term within the 午 month pillar — the inflection point where yang energy peaks and begins descending. For BaZi practice, charts cast around 夏至 carry the maximum fire-strength, but practitioners also note the immediate pivot toward yin: the period after 夏至 is when fire begins consuming itself, and water-strengthening considerations enter the chart reading.
QMDJ (Qi Men Dun Jia) relevance
Yin Dun begins at 夏至 (Summer Solstice). The Summer Solstice is the second foundational pivot of the QMDJ year — yang energy reaches its maximum and yin begins its return. The chart-rotation direction inverts here from forward (yang dun) to backward (yin dun). In the QMDJ system, 夏至 falls within the 陰遁 (yin dun, backward-rotating consolidation) half-year. The three thirds of this solar term map to 陰遁9局 (upper), 陰遁3局 (middle), and 陰遁6局 (lower) respectively. QMDJ consultations made during 夏至 carry the dun-period register stacked on top of the solar-term's seasonal energy.
For chart-aware QMDJ reading of a specific consultation made during 夏至, see the 18 Dun Periods reference for the relevant dun-period pages, or book a QMDJ forecasting consultation.
Observed register for 夏至 births
夏至 carries the register of peak achievement at the moment of pivot — visible success that immediately demands the question of 'what next?'. Born around 夏至 often carries a strong instinct for both achievement and the pivot away from over-extension.
Why generic Summer Solstice interpretation fails
The solar term is one structural layer of a BaZi chart, not the whole chart. The actual reading for someone born around 夏至 depends on the day pillar (the Day Master), the year and hour pillars, the chart's elemental balance, and the upcoming luck pillars. Generic per-solar-term descriptions can name the foundational seasonal register, but they cannot tell you what your specific chart says. Master Sean Chan’s BaZi consultation reads the full chart against your specific question.