Chinese Era Names and Gregorian Years (140 BCE – 1911)

Last revised: 2026年10月18日

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Chinese reign titles (nianhao) run from Emperor Wu of Han’s Jianyuan 1 (140 BCE) to Xuantong 3 of the Qing (1911): 521 era names in all. This page converts between those era names and Gregorian years, and gives the sexagenary (ganzhi) designation of each era’s first year.

The primary source is the appendix “Chinese Era Names” in the Revised Mandarin Dictionary of the Ministry of Education (521 entries); the check source is the “Index of Chinese Era Names” of the Institute for the History of Natural Sciences, Chinese Academy of Sciences (520 entries). The two tables were compared entry by entry by machine: 504 year-ranges agree. The one gap in the check source, the Western Han era Guangguang (43–39 BCE), is present in the primary source and is followed here.

This is a conversion tool, not a work of historiography. Differences and shared defects of the two sources are transcribed as they stand and noted under “Scope and doubtful entries”.

Full table (521 entries)

Grouped by period into 14 blocks. Columns: era name | first year | last year | ganzhi of the first year | years in use.

Definitions and method

Era reckoning and Gregorian years are not in one-to-one correspondence. An era could be changed within a year, so a single Gregorian year may contain two or more era names in succession. Both are kept here; neither is dropped.

“Year N of era E” = Gregorian year (first year of E − 1 + N). Thus Jianyuan 3 = 138 BCE.

Gregorian to era name: every era in use during that Gregorian year is listed, with the ordinal year of each. The “year” of an era is counted in calendar years of its use.

Ganzhi: the sexagenary designation is read from the remainder of (Gregorian year − 4) modulo 60, remainder 0 being jiazi. This rule was checked at two points against the Purple Mountain Observatory's Calendar 1900–2025: 1900 is gengzi and 1909 is jiyou, both matching. The ganzhi year begins on the first day of the first lunar month.

Years are shown and entered throughout as “N BCE”, written with a minus sign (140 BCE is entered as −140). For the ganzhi computation the year is first converted to astronomical numbering: year N BCE is astronomical year −(N − 1), and there is no year 0 — so 140 BCE is −139.

Scope and doubtful entries

Range: 140 BCE to 1911 (Xuantong 3). Nothing outside the range is extrapolated.

The two sources are near-isomorphic — same start at Jianyuan, same end at Xuantong, differing by one entry — and may descend from a common ancestor. The table is therefore offered as a conversion tool, not as a basis for historical research.

Doubtful entries are transcribed from the primary source without alteration:

① Tang “Sisheng”: the primary source gives 684–704, and the check source agrees. Sisheng was in use for one year only (684); the long span presumably absorbs the Wu Zhou era names that follow. Transcribed as it stands.

② Northern Song “Yuanxi” 1017–1021: both sources agree. The era of Emperor Zhenzong for those years is usually written Tianxi. Transcribed as it stands.

③ Northern Wei “Shenjia” 428–431: the character is corrupt in both sources (a hash sign in one, a private-use codepoint in the other). It is restored here from a third source as 䴥.

④ Wu (Three Kingdoms) 275–276 “Tiance”: the character is a private-use codepoint in the primary source; the check source is followed here as 册.

Reckonings beginning in 1912 (Republican years, the Manchukuo era Kangde and the like) are outside this page.

References

Ministry of Education, Revised Mandarin Dictionary, appendix “Chinese Era Names”, 521 entries. dict.revised.moe.edu.tw

Institute for the History of Natural Sciences, Chinese Academy of Sciences, “Index of Chinese Era Names”. agri-history.ihns.ac.cn

Purple Mountain Observatory, Chinese Academy of Sciences, Calendar 1900–2025, compiler's notes. nddc.pmo.ac.cn (used to check the Qing era names and the ganzhi year boundary)

Character readings: Unicode Unihan database, kHangul field. Japanese shinjitai: OpenCC JPVariants table.

Related pages: Julian Day and Ganzhi Day Count | Time Scales and Standard Time | Calendar Converter (Gregorian, Chinese, ganzhi, solar terms) | Five-Field Matrix of 52 Chinese Calendars