with Lisa Louise Cooke
Welcome to this step-by-step series for beginning genealogists—and more experienced ones who want to brush up or learn something new. I first ran this series in 2008-09. So many people have asked about it, I’m bringing it back in weekly segments.
Episode 43: The Julian Calendar and Genealogy “Double-Dating”
If you’re not familiar with how the calendar has changed through history, you might be recording incorrect dates in your family tree! In this episode, Margery Bell, Assistant Director of the Regional Family History Center in Oakland, California helps us understand the “double-dating” we see in old documents and translate those dates from the Julian calendar to today’s Gregorian system.
The Julian Calendar
In 1582, the Roman Catholic Pope Gregory learned that gradually the vernal equinox wasn’t coming on the “right day.” At the time, the first day of the new year was March 25. This explains why the name of September (“sept”=seven) translates as “the seventh month: and October (“oct”=eight) as the eighth month, etc.
So in 1582, the calendar changed in the four countries under papal authority: Spain, Portugal, Italy and the Polish-Lithuanian state. Gradually over time, everyone else adapted to what became called the “Gregorian calendar,” and is what we use now. But you might be surprised how long the Julian calendar was still used in some places: Greece held out until 1923.
Great Britain changed over to the Gregorian calendar is 1752—and so did its colonies. But here in the North American colonies we were affected by the change long before because we had people here from so many nations in which either calendar might be used.
The solution in U.S. colonial record-keeping was “double-dating.” Maybe you’ve seen a date that reads “3 February 1685/6.” That means it was 1685 by the old Julian calendar and 1686 according to the Gregorian calendar. You’ll see this double-dating used between January 1 -March 25, when the time frame overlapped. You might also see a single date with the abbreviation “o.s.” or “n.s” for “old style” or “new style,” or you might see those words written out. If it’s written in the new calendar style, of course, you don’t have to translate the date.
Why does it matter to a genealogist which style is used? If you don’t translate the date correctly, you’ll get confused about timing. The change from one calendar to the next involved dropping several days from the calendar in 1752, then renumbering the months. March was the first month of 1725, for example, and January 1725 actually came after it—that was the eleventh month! It will look like people have their will probated before they died, or they had a baby before they got married.
Top tips from Margery Bell:
- If you don’t see double-dating in a colonial document before 1752, assume you’re on the old calendar. See a sample at George Washington family bible with birthdate. (Listen to the podcast to see how his birthday as celebrated today was translated out of that calendar.)
- Some vital or church records may be written as “the second day of the third month.” If they were following the old calendar, we will “translate” that date incorrectly if we don’t know better. Go back and double-check the sources for your older dates. That includes making sure that any dates you copied from an index (if you couldn’t get to the original record) were indexed accurately.
- FamilySearch has a lot of data from the IGI, the International Genealogy Index. These older records include a LOT of Julian calendar items but the IGI doesn’t indicate whether that’s true. If you see two different marriage records for the same couple married on two separate dates, translate them and see if one is perhaps the adjusted date and the other didn’t get “translated.”
Genealogy Gems Mailbox
Women should be entered in family trees with their maiden names. Then they are linked to men they marry in family trees, and that’s how you can determine their married surname. I double-checked with the Ancestry Insider blogger about Ancestry searches. He says that Ancestry “shaky leaf” hints search on both a woman’s maiden name and all her husband’s surnames. Thanks for that extra tip, Ancestry Insider!