50,000 More Dates

No, not at Match.com, but at Historical Financial Statistics. Our apparently unique calendar spreadsheet (accompanied by a detailed documentation file) shows dates from 1500 to the present according to ten calendars: Julian day number, Julian, Gregorian (the standard calendar for most of the world today), traditional Chinese, Ethiopian, French Republican, Hebrew, Islamic, Iranian, and Ottoman.

There are, however, some gaps. One that has just been filled concerns Chinese calendar dates during the Ming Dynasty (1341-1644). Keith Hazelton, an information technology guru, used his expertise to calculate the correspondence of dates between the Chinese calendar and Western calendars in an old research paper I only recently came across. He has kindly allowed Historical Financial Statistics to use his data.

Some other gaps remain. The Iranian (hijri) calendar was reformed in 1925, and mechanically extending the current rules backwards does not always give correct dates. The Hebrew calendar is complex, and I could only readily find dates in spreadsheet format since since the founding of the State of Israel. The Buddhist calendar is not shown at all in the spreadsheet because I could not readily find easily usable information on its correspondence to Western calendars. I would appreciate any information readers can offer to fill these gaps or to include other calendars that have been important in some part of the world over the last 500 years.