Awakening day sesshin

awakening day sesshin (rōhatsu sesshin 臘八攝心)

A sesshin that commemorates Shakamuni Buddha's attainment of awakening, traditionally said in East Asia to have occurred on the "eighth day" (hatsu 八) of the "last month" (rō 臘): the 12th month in the lunar calendar. In modern Japan, December 8 is set as the day for Buddha's attainment assembly (jōdō e 成道會). The awakening day sesshin typically culminates on the dawn of that day, at the time when the Shakamuni is said to have seen the morning star and attained buddhahood. →"sesshin."

Source

global.sotozen-net.or.jp