March 21 (Wed)
Shunbun (春分) is the 4th of 24 solar terms (節氣) in the traditional East Asian calendars.
It is the Vernal Equinox Day.
In Japan, this day is a holiday for “the day to praise nature and love creatureds”.
It is also the middle day of equinoctial week (higan / 彼岸), in which people visit graves of ancestors and visit temples.