Spring Equinox Day is called Shunbun-no-hi in Japan. Shunbun means the day when the day and night are of equal length. Since it is usually around March 21st, the day is designated a national holiday. I understand it is very important for Japanese people when spring starts. We also call the week "Higan". We believe the spirits of ancestors return to this world during higan. So, we wait for our family spirits after we clean our family graves and offer flowers to them.