# September 23
Autum Equinox Day (shubun no hi):
Graves are visited during the week (ohigan) of the Equinox Day. The day itself is a national holiday.

One of the most traditional Japanese National Holidays, this holiday seems to have a double origin. One is the celebration of seasonal change typical of an agricultural society: this is the day when the day-time and the night-time are of equal length. The actual date of the Fall Equinox Day may change from year to year due to leap year, but is generally around September 23rd. From this day on the night-time hours will be longer than the day-time hours, until the winter solstice in late December, the shortest day of the year. . This autumnal Equinox Day is also called HIGAN NO CHU-NICHI, which is based on Buddhist teaching. Many Japanese visit their family tombs on this day in the middle of the week of HIGAN to pay their respects to their ancestors. People weed their family tombs and leave flowers, incense and ohagi (sweet rice balls covered with soybean paste.) It is tradition that ancestors' spirits prefer round food! Since ASIJ is next to TAMA BOCHI (Tama cemetary) one of the largest cemeteries in the Tokyo area, we often experience heavy traffic on trains and highways on this day.
Japanese consider this period the changing of the season, because it is usually around HIGAN that the summer heat wave covering the Japanese islands weakens, and the weather changes to autumn. There is another HIGAN in spring, at the time of the Spring Equinox. Thus we have a saying "Atsusa samusa mo Higan made" ("Heat and cold last until Higan")
Info from
http://www.japan-guide.com/e/e2062.htmlhttp://www.asij.ac.jp/elementary/japan/jp_holi.html