24 July 2023

ICYMI - Repost: Dual-year dates and other calendar anomalies explained

Originally posted on April 21, 2017

When I first started my family history research, I quickly ran into some older date notations I didn’t understand. They were listed as two years instead of one. For example, I would see a birth listed as 21 January 1680/1. I had no clue what that meant, and no one to ask.


I did, however, have the Internet and I assumed that I would only be one of many amateurs who were confused by this, so I looked at Ancestry.com, at the New England Historic Genealogical Society website (AmericanAncestors.com) and other genealogy sites, thinking this would surely be addressed in their FAQ section or on some “basics of research” page. I was wrong – I could not find any such explanation anywhere.

I did further research, finally finding a Wikipedia entry, which I paraphrase below.  At the end of this post, there is a link to the article (very interesting reading).

One depiction of a multi-year date from a Robert Hicks sketch
Another depiction from a William Mann sketch