" This year by an Act of Parliament it was approved that the Civil and Ecclesiastical year should begin on the first of January 1752 and by the Same Act the Stile was altered from the Julian to The Gregorian Account by the Annihilation of eleven Days in the month of September 1752" (extract from Ardingly parish registers)
As it often turns out nothing in family history is straight forward and there are many pitfalls for the researcher. One such pitfall is the change to our calendar in 1751.
The calendar we used to use pre 1752 was introduced by Julius Caesar in 45BC (and known as the Julian calendar) and it was a fairly accurate calendar – each year was only out of sync with the solar year by 11½ minutes. Not much but by the 16th century this had accumulated to a difference of 10 days! Pope Gregory XIII took the view that 10 days was too much (it upset the timing of Easter!) so he had a new calendar devised which was far more accurate – it is only out of sync by 26 seconds per year. Introducing the calendar however was less than easy – most Catholic countries followed his papal bull instructing the move from the Julian calendar to the Gregorian calendar in 1582 but England was no longer a Catholic county having split in 1531. In the intervening years a strong anti-Catholic feeling had developed so there was little chance of us doing anything suggested by a pope however sensible it might be! We continued with the Julian calendar but by the mid 18th century we were 11 days out of sync and it was finally time for us to accept the Gregorian calendar.
Another complication was that prior to 1751 the official new year began on the 25th March (also known as Lady Day) although the popular start to the year was the 1st January. Other countries had already begun to use the 1st January as the official start of the new year; Scotland had started in 1600 so James VI would have been used to working with a year that began in January but when he became James I of England he would have had to change to a year that began in March.
The Calendar (New Style) Act 1750 changed all this. As a result 1751 became a short year running from 25th March to the 31st December and the following year 1752 ran from 1st January to the 31st December but missed out 11 days in September, a period chosen for having the fewest festivals and saints days. Effectively our ancestors went to bed on the 2nd September and woke up on the 14th September.
I have read and heard it repeated many times that people rioted about the loss of their 11 days but nowhere have I seen any evidence for this, none of the documents which refer to these riots actually gives a source or names any parish. It is far more likely that if there was any disruption it was because people were afraid that debts such as rent and tax would become due 11 days earlier. In fact such dates were simply moved forward 11 days so they were paid after the usual number of days had elapsed but most dates remained on the same day so in most cases saints days, festivals and birthdays remained on the same day they had always been. However some people like to add to the confusion - George Washington was born on the 11th February 1731 (1732 according to the Gregorian calendar) but with the change of calendar he moved his birthday forward by 11 days and began celebrating it on the 22nd February (the date on which America bases its federal holiday). By the way, the 25th March plus 11 days and accounting for a leap year which didn’t happen takes us to the 6th April – still the start of the tax year.
So how does this affect family historians? It sounds fairly straightforward but as I said at the beginning nothing is straight forward in practice. Many people used the 1st January as the start of the new year long before 1751, the parish registers of Arundel in West Sussex were already starting their year in January whilst the Horsham parish registers ignored the change and did not start the year with 1st January until 1764.
And it does matter – a child baptised on the 3rd February 1658 can be a sibling to a child baptised on the 28th March 1658 whilst a couple can marry on the 8th May 1732 and have a legitimate child baptised on the 21st January 1732. When you use indexes and transcripts you should always check to see if dates have already been converted to the Gregorian calendar – is it the 5th February 1702 (old style) or 5th February 1703 (new style). There is also the issue of how you write dates pre 1751? I generally use 5th February 1702/1703 whilst others prefer 5th February 1702 (os) to indicate old style/Julian calendar or 5th February 1703 (ns) to show new style/Gregorian calendar.