From time to time, the contentious topic of historical accuracy in historical fiction rears its pointy head, where one camp succinctly points out that it’s FICTION, and that gives it sufficient license to “bend” history. The other camp takes exception to this license, since the works are based on real people, and we owe it to them to be as accurate as possible. This camp of authors—I among them—have found ourselves obsessing over dates to the point of obtaining itineraries where available and being scrupulous about not having a character in one place if records show that character in another. We save our speculation for where the information is absent or conflicted.
Adhering to the facts has spoiled many a plot point. Often, when the story has to be retooled to accommodate what is known, the story gets better, but not always. I’m happy to reveal a 170 year loophole, but only if the story takes place between October 1582 and September 1752. This is because in February 1582, Pope Gregory XIII issued a papal bull to correct discrepancies in the calendar where the solstices didn’t align. The bull decreed that ten days were to be eliminated from the calendar such that the day following Thursday, October 4, 1582 would thereafter be known as Friday, October 15, 1582 (instead of October 5th)—hence eliminating ten days from that year. Years that were divisible by 100 must also be divisible by 400 to be a leap year, and new rules were put in place for determining the date on which Easter fell. In addition, leap day was moved from the day before February 25th to the day after February 28th. (I wonder if the Julian leap day was February 24.5?)
A further complication was the day celebrated for the New Year. Not only did it vary from country to country, but also between groups within a country. So the New Year may have been celebrated in March, January, or December. This bull also set the New Year to January 1st.
The bull was issued after Great Britain broke with the Roman Catholic Church. Great Britain did not adopt the new calendar until September 1752, when September 14th immediately followed September 2nd.
The difference between the calendars created some problems and disparities. For example, in the colonies (now the United States) the New Year was observed March 25th, but when Great Britain adopted the Gregorian calendar in 1752, the observed day was pushed back to January 1st. As a result, those born between January 1st and March 25th suddenly found their birth year advancing by a year. Imagine having to wait an extra year to collect social security or being able to legally drink because your calendar suddenly changed? While George Washington didn’t have to worry about social security or a legal drinking age, he might have not made the cut-off legal age to be president if he had been born ten years later than his actual birth on February 2, 1731 (Julian)/1732 (Gregorian).
So rejoice historical fiction writers of the late 16th, the entire 17th, and first half of the 18th centuries—here is your loophole. Or curse, because it’s also your dilemma. Suppose your character is English, but the documents you are referring to were translated from the French. Were the dates in Julian or Gregorian? How did people who traveled between the countries reckon the dates?
Reference: The Julian and Gregorian Calendars by Peter Meyer