We finally managed to make the Korean Calendar data part of our time authority database, which is now the first open-source CJK calendar dataset available. As usual we provide a simple interface (
authority.ddbc.edu.tw/time/), but the main value is that with the downloadable archives
and at GIT hub
it is possible for researchers to use the data in their own way.
The construction over the last three years of the CJK-calendar database has proved again one of the principles of digitization: complexity arising out of seemingly simple tasks. To map East-Asian calendar systems with their combination of astronomical and historical ways to mark time to the (proleptic) Gregorian calendar via the Julian Date used in astronomy proved to be more difficult than expected. This in spite of a wealth of previous scholarship, comparative tables etc. on the topic.
We wish we had a complete documentation for this project, alas few of the decisions made are explained anywhere in a standardized fashion.
The CJK-calendar database is limited in the range of the dates covered. Our sources are concerned with Buddhist history and to make the project easier for us we have not included the earlier periods. Since the database is open-sourced, we hope that one day someone will add the data for these periods.
As it is the CJK-Calendar Database provides dates for the following periods:
China: 220 BCE and 1912 CE
Korea: 56 BCE and 1885 CE
Japan: 593 CE and 1872 CE
The Korean calendar dataset here should be considered an extension of the Chinese calendar data. The Korean calendar has a special relationship to the Chinese calendar and sometimes retained era names beyond their use in China, and, as the Japanese calendar, shares the same cyclical stem-branch count. In order to make full use of it you will need both the Chinese and the Korean set.