1.
doyō; 18-day period before each season change
In the traditional Japanese calendar, the ~18 days leading up to each new season (spring, summer, autumn, winter). The summer 土用 is the best known, associated with eating eel.
Originates from the traditional five-element calendar. Strictly, there are four 土用 periods each year, but in modern usage 'doyō' almost always means the summer one in late July to early August.
Common collocations
- 土用の丑の日: 'Day of the Ox' during doyō — the day to eat eel
- 土用入り: the start of a doyō period
- 土用波: rough late-summer waves
- 夏の土用: summer doyō
Cultural note
The summer 土用 falls in the hottest part of the year. There is a tradition of eating eel (うなぎ) on the 丑の日 (Day of the Ox) within this period to build stamina against the heat — a custom popularized in the Edo period and still observed today.