Rikka (立夏): Start of Summer
The day summer begins in the traditional calendar, when fresh green leaves are dazzling.
| Year | Date and time (Japan Standard Time) |
|---|---|
| 2025 | May 5, 2025 (Mon) 14:57 |
| 2026 | May 5, 2026 (Tue) 20:49 |
| 2027 | May 6, 2027 (Thu) 2:25 |
Times are found from the sun's apparent longitude (Japan Standard Time).
What Rikka means
Rikka is a setsu (節, “joint”) term: in the eto calendar the Snake month begins on this day. In Four Pillars and Nine Star Ki, the month's eto and star change at Rikka.
Customs and seasonal food around Rikka
Around the Boys' Festival on 5 May, people bathe in iris leaves to drive away evil. In season: bonito and broad beans.
The 72 kō of Rikka
Each solar term is divided again into three periods of about five days, the 72 kō (七十二候, “microseasons”). The names here follow the 1874 Ryakuhon-reki almanac. The first person to adapt the Chinese names to Japan's own climate was the astronomer Shibukawa Harumi, in the Jōkyō calendar of 1685.
| Kō | Name | Meaning |
|---|---|---|
| 1st | 蛙始鳴 | Frogs start singing |
| 2nd | 蚯蚓出 | Worms surface |
| 3rd | 竹笋生 | Bamboo shoots sprout |
1st kō: Frogs start singing (蛙始鳴)
Frogs begin to croak in rice paddies and ponds. What the Senmyō calendar's creature here was is debated, but in Japan it became the frog. Rikka is the start of summer, and on 5 May families fly carp streamers and bathe in iris leaves.
2nd kō: Worms surface (蚯蚓出)
Earthworms come up to the surface, a name shared with the Senmyō calendar. Because they till the soil, worms have always been prized in the fields. In some regions rice planting is in full swing and the early-summer sun grows stronger.
3rd kō: Bamboo shoots sprout (竹笋生)
Bamboo shoots appear. The Senmyō calendar had “the snake gourd grows” here. Some say these are the later shoots of madake rather than mōsō bamboo. The character 筍 is said to come from shoots turning into bamboo within a jun (ten days).