Friday, 1 February 2013

Calendar Calculations

   Throughout the centuries, various diaries or almanacs have been used to mark time and fix events and religious festivals within the yearly cycle


  Originally, people would set these dates to tie in with easily observed natural occurrences like the changing seasons or varying weather but the fact that these happenings were not reliable meant that an alternative had to be found.
   In 45BC, Julius Caesar established the Julian calendar which was used in Britain and the Colonies until 1751. His formula consisted of creating eleven months of 30 or 31 days and 28 in February (except on a Leap Year when this rose to 29). The calculations differed from the solar calendar by only 11.5 minutes per year but over the centuries, these minutes added up and by the 1500’s, the Julian calendar was ten days behind its astronomical equivalent.
   To correct this problem, the Gregorian calendar was created by Pope Gregory XIII in 1582. Although Britain did not take on this new schedule, other countries did. One of the main differences between the two calendars is that the Julian has a Leap Year every four years while the Gregorian does not have a Leap Year if the number is not dividable by 400 or ends in 00. Therefore, 2000 was a Leap Year but 1900 was not.
   In 1751, when Britain eventually decided to adopted the Gregorian system, eleven days had to be lost in that first year to set it in line. These were taken from the month of September when the British Calendar Act declared that Wednesday 2nd would be followed by Thursday 14th
   In the old Julian calendar, the first day of the year ran from the 25th March - or Lady Day as it was known - so to complete the calendar changeover, 1751 ran from the 25th March to the 31st December allowing the following year to begin on the 1st January.
Research Top Tip 
    If you’re able to track you ancestry back to this period, be aware that events in this year were often dated as 1750/51 when the calendar conversion took place.

Don’t Forget! 
   There may be times when you come across the Latin use of Roman numerals where a number is represented by one or more letters. Below is a quick reminder of this numerical code.
  I (i or j) = 1
  V          = 5
  X          = 10
  L           = 50
  C          = 100
  D          = 500
  M         = 1000

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