Calendars with more seasons

 While we think in terms of four seasons, the ancient Chinese thought of 24.

Ancient astronomers marked the position of the sun in the zodiac in 15-degree increments, each increment, term or season being 15 days. The arithmetic of the calendar was this: 24 terms x 15 days = 360 days. The custom was to add an extra short term, a holiday season, to get to 365 days.

It’s easy to see why the ancient poets liked the idea. The more detailed seasons prompt you to think about the recurring patterns of nature — the return of migrating birds or the appearance of the first flowering plants in spring.

One of the delightful little seasons, “Awakening of Insects,” begins March 5.

All systems have their problems, and one of the obvious problems here is that the growing seasons in northern China are not in sync with those of southern China. Several of the seasons are named for the various phases of ripening grain. They work better in one part of the country than the other. If we had a season called “Arrival of Tomatoes,” it would be hard for folks in Texas and in Minnesota to synchronize their celebrations of the first harvest.

The Japanese started with the 24 seasons used in China and developed a series of 72 micro-seasons, each 5-days long. The trend toward more seasons started early. The court astronomer revised the calendar in 1685.

The calendar has micro-seasons marking the return of the swallows, the beginning of frog singing and the blooming of irises.

Obviously, what might work in one part of Japan won’t work in another.

But I like it. It’s not really a calendar for strict scientists, but it’s a wonderful calendar for poets who are interested in nature. It’s a poetic look at the year.

• Note: Phenology, the study of recurring biological phenomena tied to the calendar, pops up occasionally in these notes. See “Maybe I should have studied phenology,” Oct. 20, 2023.