About Sonohini

Dates on the Site

Currently all dates on the site are expressed as Western dates. All dates before 1582 are Julian Calendar dates and all dates after 1582 are Gregorian Calendar dates. Most dates before the 6th century are either approximate or based on legends of dubious accuracy.

Before the Meiji Period, Japan used era names and a variety of lunar calendars to record dates. Era names were assigned by the reigning emperor and could be changed at the emperor's will. Most years had 12 months, but an occasional 13th month was added to keep the calendar inline with the seasons, much like the current Gregorian Calendar does during leap years. A typical date from pre-Meiji Japan might look something like this: 元暦2年8月14日, 2nd year of the Bunji Era, 8th month, 14th day. Due to the use of a lunar calendar, traditional Japanese dates were one to two months behind their western counterparts. The previous example (Bunji 2, 8th month, 14th day) corresponds to August 9th, 1185 in the Gregorian Calendar, almost a full month off. During the Meiji Restoration, the old calendar system was dropped in favor of the Gregorian Calendar and the era name system was changed so that an era name lasted the entirety of an emperor's reign.

Note that many sites on the internet incorrectly use the Japanese date as the Western date (i.e. 元暦2年8月14日 is the same as 8-14-1185) leading to misunderstanding and inaccuracy. I have done my best to find accurate conversions to help resolve this problem.