Crown calculus: The math behind Queen Victoria’s record reign

Patricia Treble for Maclean's

Crown calculus: The math behind Queen Victoria’s record reign

About a year ago, the royal household realized it had a problem. In September 2015, Queen Elizabeth II would pass her great-great-grandmother, Queen Victoria, as the longest-reigning monarch in Britain (as well as in Canada and 14 other realms). However, no one was sure when that historic moment would occur. Dates ranging from Sept. 9 to Sept. 11 were posited. The calculations themselves give different results, depending on whether days alone are counted; or years and days; or years, months and days.

So, to be definite, the bibliographer at Windsor Castle sat down with historical records and did some rather precise mathematical calculations to settle the arguments once and for all.

Our sister publication, Maclean’s, was given two pages of annotated calculations by the royal press office, with the proviso that they would not be published until just before the big day. Here are the royal computations, along with a few value-added snippets from Maclean’s:

Queen Victoria and Queen Elizabeth. Photos © Getty Images


Queen Victoria came to the throne on the death of her uncle, King William IV, on June 20, 1837. She recorded in her diary that it was reported to her that his death had taken place at “12 minutes past 2 this morning.”

Her reign ended at her own death, on Jan. 22, 1901. In the official bulletin, the time as given as 6:30 in the evening, although the Duke of Argyll (husband of her daughter, Princess Louise), who doubtless had insider information, states in his biography of the Queen, VRI: Her Life and Empire, p. 389, that she died at “6:35 in the evening.”

This was a reign of 63 years, 7 months, 2 days, 16 hours, and 23 minutes.

However, because both years and months vary in length, the less ambiguous measure is to calculate the total in days, hours and minutes. This takes into consideration the years that were leap years (remember that 1900 was not a leap year, unlike 2000), and the lengths of the various months between June and December. On this calculation, she reigned 23,226 days, 16 hours and 23 minutes.

This consists of:

  • June 21 to Dec. 31, 1837: 194 days
  • 1838 to 1900, i.e., 63 calendar years of 365 days plus 15 leap days: 23,010 days
  • Jan. 1 to 21, 1901: 21 days
  • Remaining hours of Jun. 20, 1837 (21 hours, 48 minutes) and majority of hours of Jan. 22, 1901 (18 hours, 35 minutes) = 1 day plus 16 hours 23 minutes

Total: 23,226 days, 16 hours, 23 minutes


Her Majesty came to the throne on the death of her father, King George VI, on Feb. 6, 1952. The exact time of his death is not known: He was seen at his bedroom window around midnight on Feb. 5, and is thought to have died in the very early hours of Feb. 6 in his sleep (so exact minutes become somewhat academic in the calculation).

Assuming the time was around 1 a.m. that morning, the Queen will pass her great-great-grandmother’s record around 5:30 in the evening of Sept. 9, 2015, again calculating number of days.

This consists of:

  • Feb. 7 to Dec. 31, 1952 (including the leap day): 329 days
  • 1953 to 2014, i.e., 62 calendar years of 365 days plus 15 leap days: 22,645 days
  • Jan. 1 to Sept. 8 [2015]: 251 days
  • Remaining hours of Feb. 6, 1952 (23 hours approximately) and majority of hours of Sept. 9, 2015 (17 hours, 30 minutes) = 1 day, 16 hours, 30 minutes approximately

Total: 23,226 days, 16 hours, 30 minutes approximately

Read the original story at, and see more articles by Patricia Treble here.

Read More: Find out what Queen Elizabeth and her great-great-grandmother Queen Victoria have in common besides time on the throne (think husbands and horses!)

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