Autumn equinox is a seven-day period centered around the autumnal equinox, including the three days before and after, during which people offer prayers for their ancestors, visit their graves, and clean their Buddhist altars. On the autumnal equinox, when the sun sets directly in the west, people turn their thoughts to the Buddhist paradise of the Pure Land in the west and express their gratitude to their ancestors. During the equinox, it is customary to offer " ohagi " (rice dumplings), and in addition to visiting graves, people also clean their Buddhist altars.