关于中国的王位纪年

中国在商代之前，无纪年法，亦无纪年。西周成王以后，采取以君王在位年数为序的王位纪年法。其中个别诸侯升王改元，年数从新计算，这才产生了前元、后元之分。汉初为了术数的忌讳，怕遇到“12”这个数字，所以就几年一改元，于是有前元、中元、后元之称。汉武帝时，提出以“天瑞”今年，但一般都是先改元，然后追命年号，甚至有改元后没有命年号的。改元、建元都在年初，新君即位，不逾年不改元。但东汉以后，开年中建元、改元之例，才不管什么遗年不逾年了。唐代有皇帝创改元最多纪录，武则天的年号就有17个之多。明清时代，才一帝一年号。辛亥革命取消年号，以建国纪年。中华人民共和国诞生，改用公历，结束了以国纪年的历史。

On the Five Figure Annals in China

There were not any way of numbering the years and no annals before Shang Dynasty in China. Emperor Cheng of Western Zhou began to adopt the annals of throne which took ordinal number of year when an emperor reigned as chronological order. In the beginning of Han Dynasty,a change of reign title often occurred but a few years afterward due to taboo of blind faith. Emperors of Tang Dynasty Changed the title of a reign frequently. In Ming and Qing Dynasties,an emperor adopted a reign title. The Revolution of 1911 cancelled the reign title and desingated the years starting from the founding of Republic. The People's Republic of China began to use the Gregorian Calendar.