The Vernal and Autumnal Equinox holidays (shuubunnohi) are national holidays in Japan. It is the beginning of Spring. Day and night are equal length this day. In ancestral times, around the world, these days were recognized as important seasonal markers. In fact, many older cultures used either one or the other to mark the beginning of each new year. The date for the beginning of Spring can vary slightly, usually landing on either March 20th or 21st.