Vernal Equinox Day (春分の日, Shunbun no hi). Though Vernal Equinox Day became a public holiday only in 1948, this holiday is one of the most ancient Japanese holidays closely associated with religious tradition. On the one hand – it owes its origin to shinto (a tradition of celebrating seasonal changes), on the other hand – to Buddhism (worship of ancestors’ cult). Many Japanese visit their ancestor’s graves, conduct various memorial services and serve ritual dishes on this day. The most well-known dish of the holiday is bota-mochi – rice rolls covered with red beans paste boiled together with sugar.
They say that the Spring comes into force on this day, the Day vanquishes the Night, and the Nature returns to life and revives. Sakura will soon begin to blossom and you can in full experience enjoyment of hanami – a term for the Japanese tradition of enjoying the beauty of flowers (literally hanami means "flower viewing”).
Exact dates of the Vernal Equinox Day (as well as the Autumnal Equinox Day) and hence the holiday for the coming year is determined by the National Observatory of Japan on February 1st of the current year by making necessary astronomical calculations and measurements.