- Festival day. The particular day on which a festival is held. Dates for seasonal festivals are determined according to the season and the calendar. After 1872 the European solar calendar replaced the Sino-Japanese lunar calendar, introduced in 861 and modified in 1683. In addition, a new and simplified imperial ritual calendar was established and shrines were expected to calibrate their festivals to the imperial nenchu gyoji. The introduction of the solar calendar initially disrupted the ritual year. Most festivals were transposed from the lunar date to the same day of the month in the solar calendar and the date made permanent. The majority of festivals are fixed in this way, which means they may be held about a month later in the year now than they used to be. However there is still a significant number of festivals whose dates are determined by the lunar calendar and which therefore take place on a different (solar) date each year, hence some fluidity about the boundaries of 'summer' 'winter' festivals etc. compounded in a centralised system by the Japanese climate which varies substantially from the south to the extreme north.
A Popular Dictionary of Shinto. Brian Bocking.