The day pillar for Monday, 21 December 2026

Day pillar	己巳 (ji si)
Heavenly stem	己 (ji)
Earthly branch	巳 (si)
Day element	Earth 土 (tu)
Polarity	Yin
Solar term	冬至 (dongzhi)
Month pillar	庚子 (geng zi), governed by 大雪 (daxue)

Today's day pillar is 己巳 (ji si), a yin Earth day in the sixty-day cycle. Today is also the solar term 冬至 (dongzhi), one of the twenty-four stations of the solar year. The month pillar is 庚子 (geng zi), governed by the term 大雪 (daxue).

冬至 (dongzhi), winter solstice

冬至 is the shortest day and, in this tradition, the exact point where the light starts coming back.

Falling around the twenty-first of December, it is the mirror of 夏至 (xiazhi). The classical phrase is that yang is born at 冬至: at the very bottom of the year, the movement has already reversed.

It is a medial term at the centre of the 子 (zi) month. Historically it was one of the most important days in the Chinese year, and in some periods the calendar's count of the year was reckoned from it rather than from spring.

The tradition treats the darkest point as a turn rather than a low. That framing is why the same calendar can name a hard season plainly and still not read it as doom.