You may find many flyers that says “Doyou-no-Ushi-no-hi” at the end of July and selling eels everywhere. But what is Doyou-no-Ushi-no-hi? And why do they eat eels?
1. When is Doyou-no-Ushi-no-hi?
“Doyou” is about 18 days of the period between the seasons in ancient Japanese calendar. Therefore, there are 4 Doyou period in an year, and the summer Doyou is around the end of July to the beginning of August.
“Ushi” (Ox) is one of the 12 signs in Chinese zodiac (jyuni-shi). The 12 signs are assined to each day in order.
So Doyou-no-Ushi-no-hi is the “Ox” day of the period between the seasons, and the date differs each year. Since “Ox” day comes once in 12 days, there may be 2 “Ox” days in the 18 days of Doyou period depending on the year.
2. Why do people eat eels on Doyou-no-Ushi-no-hi?
In Edo period, there was a belief that you will not suffer from the summer heat if you eat food starting with the “U” (oo) sound, such as “umeboshi” (pickled plum) or “uri” (gourd).
However, “unagi” (eel) was known as the food eaten in winter, so the eel restaurants were at a loss how they could sell eels.
When Gennai Hiraga, a well-known scholar heard this, he put up a flyer on summer Doyou-no-Ushi-no-hi saying “Today is the Midsummer Day of the Ox” in front of the restaurant. This tradition spread gradually among the eel restaurants, and people began to make it a rule to eat eels on Doyou-no-Ushi-no-hi in summer.
3. How good is eating eels at summer?
Although it has been the custom to eat “U” sound food not suffer from the summer heat, eels contain plenty of Vitamin A and B which actually effective for preventing from summer heat fatigue and anorexia.
To get over the hot and humid summer days in Japan, try eating eels on Doyou-no-Ushi-no-hi to regain energy and stamina!!