Gregorian Calendar v. Julian Calendar

+11 votes
I have seen several different questions about the difference between the two calendars. I sometimes forget myself top remember the both calendars. It can make a difference. Here is what I put together.

Britain did not start using our current Gregorian Calendar until 1752. Before this time the new year began on 21 March rather than 1 January. So this means, that if 1 January 1750 is mentioned in old records it is actually 1 January 1751 using our current calendar. Some church records often note the year as “1750/1″ for dates between 1 January and 20 March to emphasize this. I doubt if they describe the difference.

Our current Gregorian calendar was 11 days out from the old Julian Calendar so in order to correct this deviation Wednesday 2 September 1952 was immediately followed by Thursday 14 September in 1952.

If anyone can correct or add onto this Please feel free to add to these dates.
in Policy and Style by Jerry Dolman G2G6 Pilot (169k points)
retagged by Ellen Smith

5 Answers

+14 votes
Best answer

In England the date of the New Year was Lady Day, the 25th of March (not 21st) We still have a vestige of  that in the tax  and financial year start on 6th April, ie  the same day  adjusted for the loss of days at the change of calendar.

Pragmatically, when dealing with family history within a Country  we don't normally start calculating what the date would be in the modern calendar, by subtracting days. It's normal to use  the devise of double dating  ie writing  Jan 30th 1651/2 . If just one date is used, as is necessary in the data field on a profile, then conventionally one uses the latter date ie 1652 but then make it clear elsewhere ie in the bio what has been done. There can be a problem when dealing with events that take place in different countries because other European Countries changed their calendar 170 years earlier (see  for examples of conflicts)

What you have to be very  careful with is transcribed or indexed dates .For example, in their catalogue, the  National Archives has the  PCC Wills  catalogued with the probate dates in New style, Ancestry has  the same wills with the probate dates as written (in this case you have the original image to check, though the probate date is not always easy to read and is written in Latin)

When you are working from an older English parish register it is usually quite clear that the year 'changes' in March. I believe that there are some parish registers that use double dates but I haven't seen one.

  I am not always certain that there is any  consistency on how datesfrom registers  are written in the index  in Ancestry or on Family search  This is particularly so in user contributed pedigree/ancestral files on Family Search. I found this set of dates the other day, the first 9 are for the same child; some are in OS ie 1713, some NS ie 1714 Family Search

The other thing is that there is a difference between England and Scotland. James VI of Scotland changed the calendar in 1600 and although he became James I of England in 1603,  the calendar was not changed  until 1752. So 30th January 1651 written in a Scottish parish register means exactly that whereas over the border in Northumberland it would refer to a date a year later.

(just to add, in older English documents, including wills, you may find regnal dates ie on the 4th day of March  in the 9th year of Henry VIII. There is a handy online calculator for those )


by Helen Ford G2G6 Pilot (348k points)
selected by Susan Laursen

This is an excellent answer. I'll just add that the idea of starting the year on Jan 1st must have been gaining ground in England long before 1752 because many English documents have years written as, say, 1671/2 at the time. I haven't seen any examples in parish registers, probably because of their chronological nature, but you often need to know the year began on Lady Day to make sense of a digitized image.

Although Hogarth's supposed Calendar Riots ("Give us back our 11 days") are now thought to be satire, it does seem that people lost out financially as rents were paid quarterly but wages earned weekly. I've never heard of any objections to the shifting of the new year to Jan 1 which was done simultaneously.

Helen thank you for correcting the date of calendar date. As for year date 1651/2 it is the reason I began this thread. As you said most genealogical sites do not allow for this. I think it should be accepted. The first place that I have noticed this was in the records for St. John the Baptist records in Keynsham, Somerset England. To me, it does not seem like a date should be taken too seriously because often the dates on records vary so widely especially from country to country and the researcher does not realize this. I did not know the difference in years between England and Scotland. A lesson in History. Do you know why there was a difference? As for Ancestry everyone has their opinions about it. Now as for Family Search, I think people would be surprised at some of the inaccuracies and how frequently they may happen. Thanks for the clarification and the explanation. of your well written answer. Now we need an accurate page on this topic to keep the years consistent..
+9 votes
To make it even more confusing, some genealogical software programs make it difficult to include the "1750/1" clarification.

Different countries adopted the Gregorian calendar at different times. Family Search Wiki has an excellent article on Gregorian and Julian calendars. [] There is a link imbeded in the article for a calculator.
by Doris Miller G2G6 (8.9k points)
Very Good reply. Thank you for the additions. The more information, the better.
I seem to recall that WikiTree used to be among the ones which didn't accept double-dating.  Is it still so?
Ros they probably don't. On the Error Report. I had errors for not capitalizing a place and for a space when I typed  == source ==   I understand their train of thought but IMHO I think  that consistency is more important than perfection.
0 votes
Thank you so much for bringing up this topic, so is it exactly 11 days in just one year or over a period of time did this change time during each year?

fellow wikitreer,

by Lisa Ryals G2G6 (9.7k points)
+1 vote

So how should we enter dates for WikiTree profiles?  For example, according to his Inquisition post mortem, dated 21 Oct. 1559, John Machell-4 made his will on 6 Feb. 1558 (pesumably old style).  The IPM states that he died "23 February last past."     Since we can't enter 1558/9 in the data fields, how should John Machell's death be entered -- 23 Feb. 1558 or 23 Feb. 1559?

by Anonymous Schmeeckle G2G6 Mach 9 (95.6k points)
edited by Anonymous Schmeeckle

New Style according to the help page

I agree with that since it what is conventionally used, (otherwise we would  all remember Charles 1 being beheaded in 1648  rather than the 1649 that is in all the history books  text of death warrant)

But I think it's important to use double dating in the biography to make it clear.


+1 vote

Wouldn’t that be 1752?

Reference from

by Pat Russell G2G Crew (850 points)

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