Yushui (solar term)

The traditional chinese calendar divides a year into 24 solar terms.
Yǔshuǐ / 雨水, Usui, Usu, or Vũ thủy, literally meaning rain water, is the second solar term.
It begins when the Sun reaches the celestial longitude of 330° and ends when it reaches the longitude of 345°.
It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 330°.
In the gregorian calendar, it usually begins around 18 February and ends around 5 March.

Pentads

Each solar term can be divided into three pentads, first, second and last ones.
In Yushui each pentad includes :
; in China,

first pentad / 獺祭魚 : 'otters make offerings of fish'. As fish begin to swim upstream, they are hunted by otters, which are believed to offer the fish to heaven;
second pentad / 鴻雁來 : 'the wild geese arrive'. Wild geese begin to make their northward migration, following the onset of spring;
last pentad / 草木萌動 : 'trees and grass put forth shoots';

; in Japan,