One of the 24 seasonal division points by which the solar year
is divided under the traditional Chinese calendar according to the
sun's apparent movement on the ecliptic, with the Vernal Equinox
marking 0º on this imaginary line and each of the 24 points spaced
by 15º from the next. The traditional Chinese calendar, however,
starts the solar year the Beginning of Spring marking the sun's
position at 315º, to suit seasonal changes in the North China Plain
and the Lower Yangtze Basin.
(China.org.cn)