Calendar History

[Deeman]

The Julian calendar was adopted in 45BC. The Gregorian calendar, the calendar system we use today, was first introduced in 1582 by Pope Gregory XIII.

The lengths of the months we use today were defined by Augustus Caesar (slightly modifying those of Julius Caesar). Julius Caesar instituted 1 January as the first day of the year, partly to honour the month's namesake, Janus, the Roman god of beginnings, whose two faces allowed him to look back into the past and forward into the future.

In mediaeval Europe, Christian leaders temporarily replaced 1 January as the first day of the year with days carrying more religious significance, such as 25 Dec (the anniversary of Jesus' birth) and 25 March (the Feast of the Annunciation, known as Lady Day, when archangel Gabriel announced to Mary that she would give birth to Jesus).

In Britain, New Year's Day became 25 March from 1155.

But by the 16th century, scientists agreed that the old calendar improperly calculated the length of a year and was therefore falling gradually behind. During the reign of Pope Gregory XIII, a new calendar, the Gregorian calendar, was created in 1582 that dropped 10 days (at that time) from the existing calendar, and he re-established 1 January as New Year's Day.

Scotland was not yet united to England and the Scottish government decided that 1 January made a better New Year's Day than 25 March, so the decision was made to make 1 January 1599 the new 1 January 1600. As a result, 1599 had only nine months. But Scotland did not adopt the Julian calendar, so year after year in Scotland, as in England, the days fell gradually further and further behind the Gregorian calendar.

The Gregorian calendar started to be adopted by most of Europe, but England and Henry VIII had broken with Rome and therefore did not adopt the new calendar.

The British Calendar Act of 1751 led to Great Britain (including Scotland which was now united to England) and the British Empire to adopt the Gregorian calendar. The 31 December 1751 was followed by 1 January 1 1752 resulting in 1751 being only nine months long (excepting Scotland) and, to correct the discrepancy of days (now 13), Wednesday 2 September 1752 was followed by Thursday 14 September, reducing September to 19 days. It is for this reason that the UK tax year ends on 5 April, being eleven days on from the original quarter-day of 25 March.

The convention for giving dates between 1 January and 24 March prior to 1752 in Great Britain is to use a notation giving two dates, the first being under the Julian calendar and the second under today's Gregorian calendar, e.g. 17 Jan 1545/6.

[FosseWay]

Thanks for this summary!

From a numismatic perspective, having New Year's Day on 25 March has a strange effect on one series of coins in particular: James II/VII's promissory "Gun Money" issues, struck between his flight from Great Britain and the aftermath of his final defeat at the Battle of the Boyne (1688-90). Presumably to make it easier to account for them when they were redeemed (they never were, btw), they were minted with both month and year.

There are coins dated March 1689 and March 1690 in this series. These are consecutive: "March 1689" means 1-24 March 1690 in the Gregorian calendar with NYD on 1 January, and "March 1690" means 25-31 March 1690. The 1-week issue period of the latter must be one of the shortest periods of issue for coins that is explicitly stated on the coins themselves.

More info on Gun Money here.

[brandm24]

Thanks for the interesting history lesson, Deeman.

I was always curious about why the date on the Gun Money coins included the month as well as the year. What you say, FosseWay, makes sense to me. I never came up with a reason myself.

Bruce

[krishna]

Wow, thanks a lot for the detailed insight

[Figleaf]

Indeed, Britain came late to the Gregorian calendar. A sign of isolationism? Yet, the country was not yet in its colonial heyday. It couldn't pretend global leadership, so it was in fact damaging itself by staying behind.

There were echoes of this question in Victorian times, when Britain tried and failed to decimalise, only to do it anyway decades later at greater cost and in the days when Tony Blair tried to modernise (remember "Cool Britain?") and met with resistance and ridicule. "Island mentality"?

There is also the comparison with Iran. It changed from moon years to sun years by decree, changing back when religious extremists took over. A failed experiment? An attempt to set the clock back? Insignificant?

Peter

[FosseWay]

Indeed, Britain came late to the Gregorian calendar. A sign of isolationism? 

Not isolationism, I think, but rabid anti-Catholicism.

The Julian calendar was devised by the Ancient Romans, with their empire, Latin, Classical architecture and such, that 18th century Britain wanted to emulate. The Gregorian reform, on the other hand, was implemented by a pope   ; and not just *any* pope, but the one who'd basically done to the Queen of England what Ayatollah Khomeini did to Salman Rushdie . Add that to all the institutionalised anti-Catholicism engendered by the removal of James VII/II and the Act of Settlement, and basically anything with the most tenuous connection to (modern) Rome was decried as popery and not to be trusted.

[Figleaf]

Perfectly good reasoning. The Roettiers family could be hounded out of the Tower mint only because they were branded papists.

Peter