The day pillar for Wednesday, 10 February 2027

Day pillar	庚申 (geng shen)
Heavenly stem	庚 (geng)
Earthly branch	申 (shen)
Day element	Metal 金 (jin)
Polarity	Yang
Month pillar	壬寅 (ren yin), governed by 立春 (lichun)

Today's day pillar is 庚申 (geng shen), a yang Metal day in the sixty-day cycle. The month pillar is 壬寅 (ren yin), governed by the term 立春 (lichun).

Why the days run in a cycle of sixty

Ten stems and twelve branches turning together produce sixty distinct pairs, and the calendar has been counting days through them without a break for a very long time.

Line the ten stems up against the twelve branches and step both forward one at a time. Because polarity has to match, yang with yang and yin with yin, only half the possible pairs can occur, and the sequence repeats after sixty steps rather than a hundred and twenty. That run is called the 甲子 (jia zi) cycle, after the pair it starts on.

The day count is the oldest continuous part of the system. It ignores months, years and leap rules entirely: day sixty is 癸亥 (gui hai), and the next day is 甲子 again. Sixty days is a little under two months, so any given pillar comes around six times a year.

That is why the same day pillar you have today will return, and why the number beside it is worth noticing. It tells you where in the run of sixty the calendar currently is.