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Genealogy Library: Reference Table

Dating Your Ancestors
by Marvin Kusmierz

If you are fortunate and are able to trace your ancestry back to the 16th Century, you will most likely encounter the Julian versus Gregorian calendar issue. There are many resources on the subject that cover this in depth and a few of them are included at the bottom of this page for you.

Our goal here is to provide a basic understanding as a reference for your genealogy effort. In 1582, Pope Gregory XIII implemented a change to the Julian calendar which become known as the Gregorian calendar. The change was made to correct for a drift in the dates of significant religious days and to prevent further shifting of these dates. The effects of the new calendar were:

  • 10 days were dropped from October 1582 realigning the Vernal Equinox to March 21.
  • Changed the leap year selection so that all do not end in "00".
  • The beginning of the year was changed from March 25 to January 1. Catholics and the countries where they were the dominate religion embraced the new Gregorian calendar adopting it quickly. While, countries without the overwhelming Catholic influence more slow to accept the change. The table below lists when these changes occurred.

    Julian to Gregorian Change by Country/Date

    Country - Date - (Comment):

    Austria - October to December 1583
    Bohemia - January 17, 1584
    Carinthia(Karnten) - December 25, 1583
    China - 1912 (non-Julian calendar used before this change)
    Denmark - March 1, 1700 (Protestant parts)
    England - September 14, 1752 (includes colonies)
    France - December 20, 1582
    Germany - October 16, 1583 (Catholic parts)
    Germany - March 1, 1700 (Protestant parts)
    Greece - March 1, 1923
    Holland - January 1, 1582 (Brabant, Flanders, Hennegan and a few south provinces)
    Holland - 1700 (Jul 12 Gelderland, Dec 12 Ultrecht & Overijssel), Jan 12 Friesland & Groningen)
    Hungary - November 1, 1587
    Italy - October 15, 1582
    Japan - 1873 (non-Julian calendar used before this change)
    Lusatia(Lausitz) - January 17, 1584 January 6
    Norway - March 1, 1700 (Protestant parts)
    Portugal - October 15, 1582
    Poland - October 15, 1582 (Catholic parts)
    Prussia - September 2, 1610
    Romania - April 14, 1919
    Russia - February 14, 1918
    Scotland - September 14, 1752
    Silesia(Schlesien) - January 23, 1854
    Styria(Steiermark) - December 25, 1583
    Sweden - March 1, 1753 (see reference below for earlier dates)
    Switzerland - January 22, 1854 (Catholic parts)
    Switzerland - January 12, 1701 (Zurich,Bern,Basel,Schaffhausen,Gent,Muhlhausen & Biel)
    Transylvania(Siebengurgen) - December 25, 1590
    Turkey - January 1, 1914 (Islamic calendar in use before change)
    Tyrol - October 16, 1583

    (Source: (Rundetaarn Observatory))

As you can see by the table above, the world was not in agreement on what a specific date was for a number of years during this evolution. Since most individuals never traveled outside of their own country, it really didn't affect them. But, image going through this today with our instant communications and ease of travel -- we would be in total chaos! Certainly, each of us would have an electric pocket calendar to convert TV schedules, dates of arrival in another country, time of phone calls, and the list would be seeming endless. There are some who promote a 13 month calendar to be more accurate with the solar system, but for me... I'll hold onto the current system.

Related resources:
  • The Julian and Gregorian Calendars by Peter Meyer - Very in depth explanation of these calendars and includes a tool for converting dates.
  • JOS Calendar Conversion by JewishGen - Will convert Gregorian calendar date to equivalent Hebrew calendar date.
  • World Book - Includes information on other calendars in history and links to more sites.
  • Logo ATPC