In message <[email protected]>, Adrian Bruce <[email protected]> writes > ><<snipped>> >In England, 1 January was known as New Year's Day from at least the Middle >Ages. OED gives a quote from 1393: 'The frosti colde Janever, Whan comen is >the newe yeer'. Other forms of year started on other days, including the >civil or legal year which started on 25 March, and formed the basis for most >of the dates written in years AD. ... Double dating of the form you mention >was used to avoid ambiguity; I've seen it quite widely used in documents >from the late 16th century onwards. ><<snipped>> > >Andrew, >Thanks for this. I'd actually seen that Wikipedia reference but was looking >for Leap Year references so skimmed over it, missing the significance of >when the new year could be said to start. I suspect the thing I really >hadn't twigged was that double dating isn't a modern invention to translate >their dates to ours, but something used back then, implying more than one >year number system then. > >What's interesting is that it tends to split the year number away from the >calendar in a sense - indeed, "Other forms of year started on other days" >suggests that different people would have different year numbers. Which >makes using regnal years (e.g. 5th year of the reign of King ...) rather >less perverse than my tidy mind imagined. If you have several (well, two) >year number systems, what's one more? And the ordinary peasant in the street >becomes more disconnected from the year number, suggesting that the >inability of people to know their exact ages is not only forgetfulness but >also a disconnect from the year numbers that would tell them. > >Fascinating stuff, >Adrian B > > The mistake is to suppose that the fundamental rule is "a year is a leap year if it is divisible by four". It isn't. The Julian Calendar, the reformed calendar introduced by Julius Caesar, started on the day that we now call 1 January 45 BC, but at the time was called the Kalends of January in the year in which Caesar was consul for the 4th time, without a colleague. There was no agreed system for numbering years in Caesar's Rome - the accepted way to refer to a specific year was by the names of the annual consuls. [Some Roman historians numbered the years from the foundation of the city of Rome, but they did not agree when that foundation was; later, the most generally accepted version came to be that of Varro, commencing in the year we call 753 BC, under which 45 BC would be 709 AUC (ab urbe condita = from the foundation of the city).] 1 January (the Kalends of January) was the day on which the consuls took office, and so was the start of the Roman civil year. Consequently, ever since, it has been one of the days most commonly used in Europe to start the year (25 March and 25 December being two of the others - the days on which the spring equinox and winter solstice fell around the 1st century BC, later regarded as the days of the conception and birth of Christ). So the rule in the Julian calendar is not that leap years are every year divisible by 4, but simply that they are every fourth year in a cycle beginning on 1 January 45 BC (remember when counting back that there was no year 0). But it is not quite as simple as that, because in the early years the Roman priests, who were in charge of the calendar, became confused as to how to count, and inserted too many leap years. Consequently, adjustments had to be made, and the regular 4 year cycle does not start until the year beginning on the day that we call 1 January 8 AD (the Kalends of January in the consulate of Marcus Furius Camillus and Sextus Nonius Quinctilianus). Why do we call it 8 AD (or 8 CE if we want to be politically correct)? Because we use an era invented in the early 6th century by the monk Dionysius Exiguus, in which Year 1 is derived from a probably incorrect calculation of the unknown year of Christ's birth. It is convenient (perhaps deliberate?) that he calculated it so that the existing cycle of leap years, which he inherited, causes them to fall in years divisible by 4, assuming that we use a year commencing on 1 January or 25 December. The Gregorian calendar does not fundamentally change the cycle. It modifies it by overlaying a 400 year cycle, under which the years 1600 and 2000 are leap years, but not 1700, 1800 or 1900, and so on indefinitely. The detailed calendars referred to in Pope Gregory XIII's Bull "Inter gravissimas" of 1582 make it clear that these must be years commencing 1 January. But for the 4 year cycle, the Bull expressly continues the existing cycle: "...statuimus bissextum quarto quoque anno (uti mos est) continuari debere, præterquam in centesimis annis..." "we ordain that every fourth year, as the custom is, should continue to be a leap year, except in the hundredth years...." The true answer is therefore that the leap year cycle is a count based on an arbitrary starting point, which we have maintained unbroken for a little over 2000 years, and which just happens to coincide with years divisible by four in our current numbering system. Under the calendar beginning on 25 March used in England before 1752, the first quarter of the year was numbered differently, but the leap year cycle was unchanged, so 29 February did not fall in a year divisible by 4. -- Chris Pitt Lewis

Chris, Your post is a 'keeper'. Many thanks for making it all so clear. Regards, Nancy Frey 137 Wilmot Trail Newcastle, Ontario CANADA L1B 1B9 905-623-0918 "I'm a Genealogist and I Raise Dust Bunnies as Pets." ----- Original Message ----- From: "Chris Pitt Lewis" <[email protected]> To: <[email protected]> Sent: Sunday, May 06, 2012 1:14 PM Subject: Re: [SOG-UK] Was 29 Feb 1743/44 a Leap Year Day?

What an excellent and comprehensive reply by Chris Pitt Lewis. Thank you for taking the time to write it, Chris. I am filing it for future reference. Caroline Gurney www.carosfamily.com On 6 May 2012 18:14, Chris Pitt Lewis <[email protected]> wrote: > In message <[email protected]>, Adrian Bruce > <[email protected]> writes >> >><<snipped>> >>In England, 1 January was known as New Year's Day from at least the Middle >>Ages. OED gives a quote from 1393: 'The frosti colde Janever, Whan comen is >>the newe yeer'. Other forms of year started on other days, including the >>civil or legal year which started on 25 March, and formed the basis for most >>of the dates written in years AD. ... Double dating of the form you mention >>was used to avoid ambiguity; I've seen it quite widely used in documents >>from the late 16th century onwards. >><<snipped>> >> >>Andrew, >>Thanks for this. I'd actually seen that Wikipedia reference but was looking >>for Leap Year references so skimmed over it, missing the significance of >>when the new year could be said to start. I suspect the thing I really >>hadn't twigged was that double dating isn't a modern invention to translate >>their dates to ours, but something used back then, implying more than one >>year number system then. >> >>What's interesting is that it tends to split the year number away from the >>calendar in a sense - indeed, "Other forms of year started on other days" >>suggests that different people would have different year numbers. Which >>makes using regnal years (e.g. 5th year of the reign of King ...) rather >>less perverse than my tidy mind imagined. If you have several (well, two) >>year number systems, what's one more? And the ordinary peasant in the street >>becomes more disconnected from the year number, suggesting that the >>inability of people to know their exact ages is not only forgetfulness but >>also a disconnect from the year numbers that would tell them. >> >>Fascinating stuff, >>Adrian B >> >> > > The mistake is to suppose that the fundamental rule is "a year is a leap > year if it is divisible by four". It isn't. > > The Julian Calendar, the reformed calendar introduced by Julius Caesar, > started on the day that we now call 1 January 45 BC, but at the time was > called the Kalends of January in the year in which Caesar was consul for > the 4th time, without a colleague. There was no agreed system for > numbering years in Caesar's Rome - the accepted way to refer to a > specific year was by the names of the annual consuls. > > [Some Roman historians numbered the years from the foundation of the > city of Rome, but they did not agree when that foundation was; later, > the most generally accepted version came to be that of Varro, commencing > in the year we call 753 BC, under which 45 BC would be 709 AUC (ab urbe > condita = from the foundation of the city).] > > 1 January (the Kalends of January) was the day on which the consuls took > office, and so was the start of the Roman civil year. Consequently, ever > since, it has been one of the days most commonly used in Europe to start > the year (25 March and 25 December being two of the others - the days on > which the spring equinox and winter solstice fell around the 1st century > BC, later regarded as the days of the conception and birth of Christ). > > So the rule in the Julian calendar is not that leap years are every year > divisible by 4, but simply that they are every fourth year in a cycle > beginning on 1 January 45 BC (remember when counting back that there was > no year 0). But it is not quite as simple as that, because in the early > years the Roman priests, who were in charge of the calendar, became > confused as to how to count, and inserted too many leap years. > Consequently, adjustments had to be made, and the regular 4 year cycle > does not start until the year beginning on the day that we call 1 > January 8 AD (the Kalends of January in the consulate of Marcus Furius > Camillus and Sextus Nonius Quinctilianus). > > Why do we call it 8 AD (or 8 CE if we want to be politically correct)? > Because we use an era invented in the early 6th century by the monk > Dionysius Exiguus, in which Year 1 is derived from a probably incorrect > calculation of the unknown year of Christ's birth.  It is convenient > (perhaps deliberate?) that he calculated it so that the existing cycle > of leap years, which he inherited, causes them to fall in years > divisible by 4, assuming that we use a year commencing on 1 January or > 25 December. > > The Gregorian calendar does not fundamentally change the cycle. It > modifies it by overlaying a 400 year cycle, under which the years 1600 > and 2000 are leap years, but not 1700, 1800 or 1900, and so on > indefinitely. The detailed calendars referred to in Pope Gregory XIII's > Bull "Inter gravissimas" of 1582 make it clear that these must be years > commencing 1 January. But for the 4 year cycle, the Bull expressly > continues the existing cycle: > > "...statuimus bissextum quarto quoque anno (uti mos est) continuari > debere, præterquam in centesimis annis..." "we ordain that every fourth > year, as the custom is, should continue to be a leap year, except in the > hundredth years...." > > The true answer is therefore that the leap year cycle is a count based > on an arbitrary starting point, which we have maintained unbroken for a > little over 2000 years, and which just happens to coincide with years > divisible by four in our current numbering system. Under the calendar > beginning on 25 March used in England before 1752, the first quarter of > the year was numbered differently, but the leap year cycle was > unchanged, so 29 February did not fall in a year divisible by 4. > -- > Chris Pitt Lewis