Changes

==Reign Years==

==Reign Years==

Before the year-period system was well-established, years were dated from the reigns of emperors. For example, the ''[[Nihon Shoki]]'' has dates like "in the 5th year and the 11th month of the reign of the Emperor Hatsuse-be ([[Emperor Sushun|Sujun]])." <ref> ''Sources of Japanese Tradition'',1:43. </ref> In these dates, the "first year" of a reign was counted from the beginning of the year <u>after</u> the death of the previous emperor.

The earliest year dates used in China were the reign year of the ruler. These appear on some of the 13th-century BC bone oracles and early bronze vessels. However, in the 2nd-century BC these were replaced by era names (nengô, see below), and the [[sexagenary cycle]] cycle also started to be used for years around this time. Therefore, reign years were never used for records in Japan, though the system was known from Chinese histories like the classic ''[[Spring and Autumn Annals]]'' (covering 722 to 481 BC).

 

However, the editors of the [[Nihon Shoki]] for their year dates calculated the reign years of the Japanese emperors, except for the few years for which nengô existed. Thus we have dates like "in the 5th year and the 11th month of the reign of the Emperor [[Emperor Sushun|Hatsuse-be]]." <ref> ''Sources of Japanese Tradition'',1:43. </ref>. The standard historians' dates follow the Shoki, using the later standard names for the emperors, so the above date is known as "Sushun 5."

 

In China, the "first year" of a reign was sometimes reckoned as the year a reign actually started and sometimes as the following year. However, perhaps influenced by the ''Spring and Autumn Annals'', in the Shoki, reign years, including the first year (gannen 元年), started on New Year's Day and were not retroactive, so Year 1 usually starts on the New Year ''following'' the actual start of the reign. However there are some exceptions, notably Tenji 1 (662), which is the year after the death of [[Empress Seimei]], though [[Emperor Tenji|Tenji]] did not formally become emperor until 668.<ref>Note that when dealing with Chinese, Japanese, and Okinawan rulers, and probably others from the region as well, one has to be careful of the meaning of "ascension year" in reference material. Often it refers to the year of the "1st year" of the reign year or the "1st year" of that ruler's first nengô. However, depending on the ruler, this could be either the year of or the year after the actual ascension. </ref>

==Era (''Nengô'' 年号) System==

==Era (''Nengô'' 年号) System==