Julian and Gregorian Calendars

The official calendar used in most of the modern world today is the Gregorian, named after Pope Gregory. It is based on the earth’s movement in relation to the sun with common and leap years comprising 365 and 366 days respectively.

When the old Julian calendar (which added 11 minutes every year) was replaced by the more accurate Gregorian calendar in 1582, only a few countries accepted the change. It took almost 400 years before all of Europe adopted the new standard.

Dates recorded from 1582 to 1919 that crossed the two systems can be confusing to family history researchers. For 46 years Benjamin Franklin’s birth day was January 6, 1706. He was “reborn” to January 17th when the British Colonies adopted the Gregorian Calendar in 1752.

A chart which shows when countries changed from Julian to Gregorian and a 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 here.

The Research Wiki has several entries in the Glossary about the Julian and Gregorian calendars (see Double-dating; Julian; and Gregorian entries). Unfortunately, an article about the usage of the Julian_and_Gregorian_Calendars in family history research does not exist. There are many websites related to the history of the calendars and also a site that helps with converting dates to a variety of other calendars (See Calendar Converter). In addition, there are several other articles within the Wiki that refer to either the Julian or Gregorian calendars. Each of these article could eventually be linked to this new page! If interested, please join in a community effort to write this new article for the FamilySearch Research Wiki!

When writing such an article, please consider linking it to Regnal_Years_in_England