Great Britain and the Gregorian Calendar: What is the Date?

Per Scriptum E. Wesley – Mackinac Center Intern

Much confusion in the writing of history arises from the fact that history spans a diverse array of dating methods. Because man’s knowledge is finite, his methods for discovering what is true are in constant flux. One of these changes has been the altering of the old Julian calendar to the present Gregorian calendar. Great Britain and her colonies did not adopt the Gregorian calendar until Sept. 14, 1752 (The 1752 Calendar Change). Accordingly, dating American and British history before 1752 is difficult, and merits a short discussion in any context that addresses the history of these nations.

Created in 45 B.C. by Julius Caesar, the Julian calendar was calculated to imitate the earth’s revolution around the sun, as opposed to the motions of the moon, or both the moon and the sun (ibid). Eventually, it was modified by the Christian world in an attempt to reconcile it with certain Christian festivals. March 25th was New Year’s Day; hence September was truly the seventh month, October was the eighth, November was the ninth, and December was the tenth (ibid). However, after a while, the Julian calendar was not accounting for leap years very well. It was a whole 10 days behind, adding a day for every 128 years, and throwing off the correct observances of Church seasons (ibid; History of Our Calendar). Finally, in 1582, Pope Gregory XIII proclaimed the adoption throughout the Catholic world of a “New Style” calendar now bearing his name: the Gregorian calendar (The 1752 Calendar Change). This new calendar skipped all the days between Oct. 4, 1582 and Oct. 15, 1582, and added a new requirement to what determines a leap year: leap years must be divisible by both 100 and 400 (ibid; Gregorian Calendar). Portugal, Spain, France and Italy all adopted it (Gregorian Calendar).

However, much controversy surrounded the change. The commoners of Europe thought it a landlord plot to tick them out of rent payment for over a week (ibid). Protestants opposed it, denying the authority of the Pope, and asserted that the Pope just wanted to stop Christians from worshiping on the correct celebration days (History of Our Calendar). Particularly, Great Britain obstinately held to the “Old Style” Julian calendar the longest. The Protestant Germans finally gave in during 1700, and the empire of Great Britain capitulated in 1752 (Gregorian Calendar). From 1582 to 1752 a method known as double dating was prevalent in Britain and particularly New England (The 1752 Calendar Change; Time to Take Note). A double date might be expressed as Jan. 16, 1713/14, with 1713 being the old Julian year and 1714 being the new Gregorian year. Even more complicating is the fact that although Great Britain as a nation had not authorized the “New Style,” some citizens were already informally using it (The 1752 Calendar Change). This fact alone makes dating British history between 1582 and 1752 very sketchy. For converting a Gregorian date into the Julian date, see the below formula; where “INT(x)” represents the “Integer Part” (or the “Floor Function”), “Y” stands for the Gregorian Year, “M” is the number of the month, “D” is the day, and “UT” is the “universal time” (Gregorian Calendar).

“JD = 367Y – INT(7(Y + INT((M + 9)/12))/4) – INT(3(INT((Y + (M – 9)/7)/100) + 1)/4) + INT(275M/9) + D + 1721028.5 + UT/24” (ibid)

If the Gregorian date falls between or includes a year from 1901-2099, the formula may be abbreviated as:

“JD = 367Y – INT(7(Y + INT((M + 9)/12))/4)” (ibid).

In 1750, Parliament passed the Calendar (New Style) Act, setting forth a plan to finalize implementation of the Gregorian calendar by September of 1752 [The 1752 Calendar Change; Calendar (New Style) Act 1750 (c. 23)]. The plan included the following:

“31 December 1750 was followed by 1 January 1750
24 March 1750 was followed by 25 March 1751
31 December 1751 was followed by 1 January 1752
2 September 1752 was followed by 14 September 1752
31 December 1752 was followed by 1 January 1753” (Time to Take Note).

In short, the British Empire lost the days between September 2nd and September 14th. For all dates after Sept. 14, 1752, dating British history ought to be calculated in our present calendar style. If a date pertinent to British History falls between 1582 and 1752 and the calendar style is not included, historians should take it with a grain of salt.

Sources:

Calendar (New Style) Act 1750 (c. 23): http://www.statutelaw.gov.uk/content.aspx?ActiveTextDocId=1516754

Definitions of Our Year: http://www.webexhibits.org/calendars/year-definitions.html

Gregorian Calendar: http://scienceworld.wolfram.com/astronomy/GregorianCalendar.html

History of Our Calendar: http://www.webexhibits.org/calendars/year-history.html

The 1752 Calendar Change: http://www.cslib.org/CalendarChange.htm

Time to Take Note: The 1752 Calendar Change: http://www.ancestry.com/learn/library/article.aspx?article=3358

Image of Armillary sphere with astronomical clock from Wikipedia