Old Style and New Style dating:

Great Britain was one of the last major countries to change from the Julian to the Gregorian calendar. In 1752 Britain and the American colonies officially adopt the Gregorian calendar. By that time there was a difference of eleven days between the two calendars. The result was confusion when dating events and documents in Britain and the American colonies.

An event that happened on January 1 using the Julian calendar would in essence be January 12 after the conversion to the Gregorian calendar. Another complication was that under the Julian calendar as used by Britain and Colonial America a new year began on March 25 rather than January 1. Some historians began the practice of adding "Old Style" (or "O.S.") after Julian calendar dates and "New Style" (or "N.S.") after Gregorian calendar dates.

The issue is further complicated by the fact that we do not always know if the dates we find in our sources are true to the Old Style dating or to the double dating - i.e. 1733/4 or 1733/34. I recommend that users of this website check with original sources and come to their own conclusions about the accuracy of dates.

Richard W. Baker