What Happened to the Calendars ?

Calendar of 1752 

September 1752

Year 1752 (MDCCLII) was a leap year starting on Saturday of the Gregorian calendar, and a leap year starting on Wednesday of the 11-day slower Julian calendar. In the British Empire, it was the only year with 355 days, as September 3 through September 13 were skipped.

The Julian Calendar

The Julian Calendar was introduced by Julius Caesar in 46 BC, but in those days the year number was the number of years since the founding of Rome (753 BC in the modern calendar). The original Julian calendar had 12 months starting with March of alternately 31 and 30 days with February (the last month) having 29 days - giving a total of 365 days. 

In a leap year (every forth year) the months have alternately 31 and 30 days giving a total of 366 days. Thus, in non-leap years the last month February would have 29 days is place of its usual 30. The name of the fifth month (Quintilis) was changed to Iulius (July) in 44 BC and Sextilis (Sixth month) as Augustus (August) in 8 BC.

The Change in August 

Augustus modified the Julian calendar by moving one day from February to August, so that the length of Augustus would not be shorter (and therefore inferior) than the length of Iulius, one day from September to October and one day from November to December. This gives us the scheme of days in each month that we are all familiar with.

The 11 Minute Error

Although the Julian calendar at 365¼ days per year is fairly accurate, it is in fact 11 minutes and 10 seconds too long. By the mid 1500s it was 17 650 minutes or 11.6 days adrift from astronomical time.

The Gregorian Calendar

The Gregorian calendar - also known as the New Style was introduced by Pope Gregory XIII in 1582 but was not adopted by Great Britain until 1752. It modified the Julian calendar in order to correct the accumulated errors of 11 minutes 10 seconds in each Julian year. 10 days were removed in 1582 in those countries that adopted the Gregorian calendar. Great Britain removed 11 days in September 1752 when it adopted the Gregorian calendar.

The Gregorian Reformation is assumed to have occurred in 1752 on the 3rd of September. By this time, most countries had recognised the reformation (although a few did not recognise it until the early 1900's.) Ten days following that date were eliminated by the reformation, so the calendar for that month is a bit unusual.

When the Gregorian Calendar was adopted the following significant changes occurred:

♥ Drop 10 days from October 1582 (11 from September 1752), to realign the Vernal Equinox with March 21st. The Julian Calendar, first adopted by Julius Caesar for the Roman Empire in 45 BC, had an annual error factor of .00636 days. From 45 BC to 1582 AD, the correct day of the Vernal Equinox using the Julian Calendar fell behind by a full ten days.

♥ Reduce the number of possible leap years. In the Julian Calendar, a leap year occurred every four years. By reducing the number of leap years, the Gregorian Calendar was able to more closely align the Vernal Equinox over centuries. The change was to make leap years for years ending in "00," but only if the number could be divided evenly by 400. The year 2000 is a leap year (2000/400=5), while the year 1900 was not (1900/400=4.75).

♥ Change the first day of the year from March 25th to January 1st. This was the most dramatic change from the Julian to Gregorian Calendar. Traditionally, the new year was determined by the beginning of the four seasons, and through several centuries, the first day of Spring in the Julian Calendar was on or about March 25th.

Double Dating

                        When the first day of the year changed from March to January in 1752 people began writing dates between January 1st and March 25th both ways, reflecting the "Old Style" (OS) And the "New Style" (NS), which genealogists may find indicated in old records from September 1752 forward. 

                        Someone born between 1st January and 25th March in years 1752 and before would indicate the date as 22nd February 1731/2 to indicate that in the Julian calendar they were born in 1731 but in the Gregorian calendar it was 1732. The double dating indicates the situation of a date between January 1st and March 25th. 

                         As a genealogist, any date you find in old records before 1752, and between January 1st and March 24th, inclusive, should be expressed as a double date. The authors of the documents did not do it for you in most cases. There may have been some anticipation of the calendar change in the British Empire just before 1752, but in most cases, finding a date written as 22 February 1731/2 is rare. 

                          What was written was the Julian date of 22 February 1731. After 1752, the use of double dating was widespread in the old documents. In order to calculate ages when the dates span 1752, use the second number in both cases and assume that pre 1752 years start on the 1st January.

October 1582

                               A year is not an arbitrary period of time, it is an astronomic reality insofar as it represents the time it takes for the earth to orbit around the sun. A good calendar therefore, needs to match this period of time. It takes 365.242 days for the earth to complete the trip.
                               
                               Instead of adding .242 of a day (5 hours 48 minutes and 30 seconds) to a 365-day year the leap-year system was devised. Every four years an extra day was added to the 365 days in the regular calendar thereby creating 366-day years.
                             
                              This system is relatively accurate, but .242 is not exactly the .250 of a day that it needs to be for the leap-day to work perfectly. Over the centuries the .008 of a day (11 minutes 30 seconds) began to accumulate.
                             
                               The continuing accumulation caused by the inaccuracies of the Julian calendar came to an end in 1582. Pope Gregory XIII stated that 10 days in October were to be removed from the calendar. Specifically, he struck the 5th through 14th from the month which created a very bizarre October 1582. You can imagine what people's schedule's looked like during that month

                               Pope Gregory XIII, whom the modern calendar is named after (Gregorian), also established a system to prevent the accumulation from developing all over again.

                              Every four years divisible by four would continue to be a leap year, but years divisible by 100 would not, unless they are also divisible by 400. 

                              

                              The year 2000 was one of these special years that comes once every four centuries. 2000 is divisible by 100 but also divisible by 400 and therefore it is designated as a leap year.

                              The new Gregorian Calendar is far superior to the inaccurate Julian Calendar that it replaced, but it still not perfect. There are still minuscule accumulations of time and in thousands of years, another correction may have to be enacted.

 Important event of 1582                  
                 The most interesting event of 1582 (aside from the calendar change), is that William Shakespeare (at age 18) got married to Anne Hathaway in Stratford-upon-Avon.