Source: https://mayphus.org/polychron/
Title: Polychron
Metadata: {"category":"study","id":"polychron","kind":"artifact","language":"en","route":"/polychron/","tags":["history","timeline","chinese"],"type":"project"}

Polychron

Explore 505 preserved Chinese regnal-era records. Search era names or dynasties, narrow the dynasty, and select a row to inspect its span. The bars compare the selected results on one scale; overlapping rows do not imply a single succession.

[Open the complete timeline SVG](https://mayphus.org/polychron/full-timeline.svg) · [Read the dataset](https://mayphus.org/polychron/eras.json) · [Data source and attribution](https://mayphus.org/polychron/THIRD-PARTY.md)

## About the data

The preserved dataset derives from cn-era 0.4.1, with local supplemental rows for Later Jin, early Qing and Southern Ming. Its dates and labels have not been independently rechecked for this browser view. Years are shown as BCE or CE, without a year zero. A row's endpoints describe that source record, not precise lunar-calendar dates. The 民國 row is explicitly an open-ended civil calendar: the stored value 3000 is not shown as a historical ending. Open-ended records remain searchable but are not plotted as closed spans.

## What was preserved

The original Racket work includes Chinese-numeral parsing, CE conversion in both directions, batch conversion, dynasty grouping and SVG generation. Its examples include 康熙六十一年 → 1722 CE and the reverse lookup 1722 CE → 康熙61年（清）.

The new browser explorer reads the existing public dataset. It does not restore the original converter. The full SVG and dataset links remain available without JavaScript.