Julian and Gregorian Calendars: Difference between revisions

no edit summary
m (c/e)
No edit summary
Line 5: Line 5:
The Catholic Church was very concerned because the celebration of Easter was figured from the spring equinox. As a result, on 24 February 1582 Pope Gregory XIII issued a decree (a papal bull) instituting a new calendar.  
The Catholic Church was very concerned because the celebration of Easter was figured from the spring equinox. As a result, on 24 February 1582 Pope Gregory XIII issued a decree (a papal bull) instituting a new calendar.  


To return the spring equinox to 21 March, the new Gregorian Calendar skipped 10 days from the year. Also, a change already in progress was validated - the first day of the year was changed from the 25 March to 1 January. But most importantly, to keep consistent with the earth’s movement around the sun, a new rule was followed - every year that is exactly divisible by four is a leap year, except for centurial years that are not divisible by 400. This means that the year 2000, being exactly divisible by 400, was a leap year, but 2100, 2200, and 2300, although falling in the 4-year cycle, are not leap years because they are not evenly divisible by 400.  
To return the spring equinox to 21 March, the new Gregorian Calendar skipped 10 days from the year. Also, a change already in progress was validated - the first day of the year was changed from the 25 March to 1 January. But most importantly, to keep consistent with the earth’s movement around the sun, a new rule was followed - every year that is exactly divisible by four is a leap year, except for centurial years that are not divisible by 400. This means that the year 2000, being exactly divisible by 400, was a leap year, but 2100, 2200, and 2300, although falling in the 4-year cycle, are not leap years because they are not evenly divisible by 400.  


The Pope could not mandate these changes, only make the proposal. Some countries (mostly Catholic) adopted the Gregorian Calendar soon after the Pope issued the decree. Other countries (mostly Protestant) ignored the Pope and continued with their own calendars. But gradually the advantages became apparent and most countries adopted the Gregorian Calendar (first European countries and later countries around the world).  
The Pope could not mandate these changes, only make the proposal. Some countries (mostly Catholic) adopted the Gregorian Calendar soon after the Pope issued the decree. Other countries (mostly Protestant) ignored the Pope and continued with their own calendars. But gradually the advantages became apparent and most countries adopted the Gregorian Calendar (first European countries and later countries around the world).  
Line 11: Line 11:
There is some uncertainty for the dates between 1 January and 25 March in the years from 1582 till the year the Gregorian Calendar was adopted. To avoid any confusion, write the date with both years' numbers. For example - 14 February 1699/1700. At the time it would be considered 1699 according to the Julian Calendar, then in effect. But now it would be considered 1700 according to the Gregorian Calendar. Using the double-year dating and understanding its purpose can be helpful in recording historical events.  
There is some uncertainty for the dates between 1 January and 25 March in the years from 1582 till the year the Gregorian Calendar was adopted. To avoid any confusion, write the date with both years' numbers. For example - 14 February 1699/1700. At the time it would be considered 1699 according to the Julian Calendar, then in effect. But now it would be considered 1700 according to the Gregorian Calendar. Using the double-year dating and understanding its purpose can be helpful in recording historical events.  


A [http://www.searchforancestors.com/utility/gregorian.html chart] which shows when countries changed from Julian to Gregorian and a [http://www.fourmilab.ch/documents/calendar/ converter] that translates dates from a variety of calendars are among the tools available to navigate through this maze. Interesting historical reading about how a monarch's reign influenced the English calendar is found in the article [[Regnal Years in England]].  
'''Julian to Gregorian calendar changes by country or region'''
 
Ancestor Search has published a helpful [http://www.searchforancestors.com/utility/gregorian.html chart] showing when countries and regions changed from Julian to Gregorian.
 
Fourmilab.ch has created a [http://www.fourmilab.ch/documents/calendar/ converter] that translates dates from a variety of calendars, including Julian and Gregorian.
 
Another tool that can help with Julian and Gregorian dates, especially for Germany, is GenTools6, available as a free download from [http://www.gentools6.de www.gentools6.de]. 
 
The following is partial list of countries and regions and when they adopted the Gregorian calenadar.  The chart from Ancestor Search, mentioned above, has a more complete  and detailed list.


{| class="wikitable sortable FCK__ShowTableBorders"
{| class="wikitable sortable FCK__ShowTableBorders"
377

edits