Julian Calendar and Gregorian Calendar

When was Julian Calendar Changed To Gregorian Calendar?

Happy New Year to everyone! Hoping you all have a Happy, Healthy and Prosperous new year.

Bringing in a new year reminds me that in genealogy, the years have not always been what they seem. The Julian calendar that was in use several hundred years ago, used March 25th as the beginning of a new year. Because the Julian calendar appeared to be ‘out of sync’ with the seasons, a new Gregorian calendar was put in place. I’ve provided links below that will take you to sites with more history about the various calendars in use over time as I am only addressing the change from Julian to Gregorian Calendar in this post.

This change took place in 1582 by order of Pope Gregory XIII, but wasn’t adopted by England and British North American until 1752. China didn’t conform to the Gregorian calendar until 1949. Alaska did not change from the Julian calendar to the New Style Gregorian calendar until 1867 because up to that point, it was part of Russia.

Prior to 1752 the ecclesiastical calendar recognized March 25 as the first day of the year. After 1752, the present calendar was adopted and the new historical calendar recognized January 1 as the first day. Consequently, dates between January 1st and March 25th of 1752/1753 were often written with both year numbers (i.e. 5 January 1752/53). This is referred to as double dating. Also, if a record says “The 4th day of the 2nd month it could be referring to February or April, depending upon the calendar in use at the time.

England and British North America changed their calendar in September 1752. Although people went to sleep the evening of September 4th, they woke up on September 15th and lost 11 days.. Some people added 11 days to their birth dates, which was not reflected on their birth record.

Interesting Tidbit: George Washington was born on February 11th, and changed his birth date to February 22nd, due to the lost 11 days. “The change on September 2, 1752, decreeing the next day should be September 14, thus bridging the 11-day difference between the Julian and Gregorian calendars. Thus, too, George Washington’s birth date was transposed from February 11, 1731 (Old Style), to February 22, 1732 (New Style). Since the calendar was changed in September, moving January and February to the beginning of the year, Washington did not have a birthday in 1731. He skipped a year and thus became 11 days older and one year younger.” 1


The Gregorian Calendar is referred to as the “New Style” (NS) and the Julian Calendar is referred to as the “Old Style” (OS), which may be noted in older documents.

Here are just a few examples of when dates changed to Gregorian Calendar:

1582 – Catholic states such as France (excluding Alsace (Elsaß) and Lorraine), the Italian Principalities, Poland, Spain (along with her European and overseas possessions), Portugal and the Catholic states of the Holy Roman Empire, Dutch Republic. The first to change.

1583 – Holland. Note that Netherlands was twelve different Historic areas, Holland being one of them, and the dates varied between 1583 and 1700 for the other eleven.

1612 – Duchy of Prussia – Poland/Russia

1648 & 1682 – Alsace (Elsaß) France/Germany

1657 – The Lutheran Duchy of Prussia, until 1657 was still a fiefdom of Roman Catholic Poland, was the first Protestant nation to adopt the Gregorian calendar.

1682 – Lorraine, France

1700 – Denmark, Sweden (including Finland) and Norway, although numbering the year on January 1st was a gradual change.

1752 – Great Britain, British Empire, Scotland, Ireland, American French Colonial Empire, Spanish Empire and British Empire. (Including American Colonies, not yet USA).

1867 – Alaska adopted the New Style on incorporation to the United States in 1867, which preceded adoption by Russia.

1918 – Russia (excluding the Duchy of Prussia which had already adopted the New Style).

1949 – China

This becomes even more complex as you add in French Republican and other calendars. Here are some links for more in depth information on calendars.

The USGenWeb Project
Connecticut State Library

  1.  Culkin, John M, The Year Washington Missed a Birthday, New York Times Archives, 1991. at https://www.nytimes.com/1991/03/01/opinion/l-the-year-washington-missed-a-birthday-059991.html (Accessed 26 June 2019).

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