Seasonal days (Nijūshi sekki, Zassetsu, Shichijūni kō)

Some days have special names to mark the change in seasons.

The 24 Sekki (二十四節気 Nijūshi sekki^?) are days that divide the solar year into twenty four equal sections.

Zassetsu (雑節^?) is a collective term for the seasonal days other than the 24 Sekki.

72 Kō (七十二候 Shichijūni kō^?) days are made from dividing the 24 Sekki of a year further by three.

These were named based upon the climate of Northern China, so many of the names do not fit in with the climate of Japanese archipelago. But some of these names, such as Shunbun, Risshū and Tōji, are still used quite frequently in everyday life in Japan.