The traditional Chinese calendar divides the year into 24 solar terms that track the sun and seasons. Each has a distinct energy — a rhythm farmers and astrologers have followed for millennia.
The sequence runs from Start of Spring in early February through the equinox, the solstices and back again, each term about fifteen days long. The first half of the cycle opens and grows; the second half ripens and withdraws. Because the divisions follow the sun rather than the moon, they stay aligned with the seasons — which is exactly what makes them useful for anything that depends on light and temperature rather than ceremony.
A common mistake is to treat a term as a single date. Each one names a fortnight, and the character of that fortnight matters more than the day it begins. Start of Autumn does not mean the heat is over; it means the direction has turned. Read each entry below as a description of the fifteen days it opens, and the advice becomes far more practical.
The solar terms set the calendar's structure and the twelve animals set its character. Put them together and you get the full traditional year: an animal cycling every twelve years, an element every year, and a term every fifteen days. The Chinese zodiac daily horoscope covers the animal layer for today, and the everything for today page collects the rest.
A solar term is a point on the sun's apparent path, spaced roughly fifteen degrees apart, which divides the year into 24 named segments. Unlike lunar festivals, they follow the sun rather than the moon, which is why their Gregorian dates shift by only a day or two from year to year.
Twelve divisions would only mark the months. Twenty-four give the finer granularity that farming, medicine and astrology all need — the difference between "spring" and "the fortnight when the ground is ready". Each term lasts about fifteen days and has its own weather, diet and behavioural associations.
In BaZi the solar terms mark the true boundaries between months and years, which is why the Chinese year is usually said to start at Start of Spring rather than at the lunar new year. Someone born in the days between the two can carry the animal of the previous year, so chart accuracy depends on the term dates rather than the calendar.
The term positions are fixed in the sky, so the Gregorian dates move by about a day. The table above lists the usual date for each term; around the equinoxes and solstices a term can land on the 20th, 21st or 22nd depending on where 2026 sits in the leap cycle.
The four "pivot" terms — Start of Spring, Start of Summer, Start of Autumn and Start of Winter — carry most weight because they mark the true seasonal boundaries, and the two solstices are the most widely observed. Winter Solstice is the oldest of them and was celebrated as the turn of the year long before the lunar calendar was standardised.