Dates are a sticky problem for genealogists because of the different calendars in use at different times in different countries.
England and her possessions used the Julian Calendar up until 1752.
In the Julian Calendar the new year begins on March 25. So you'll
find dates in the reports here that fall from January 1 and March 24 for
the years prior to 1753 displayed as, for example,
2 Feb 1715/16
This is to indicate that the year is 1715 according to the Julian reckoning,
but 1716 to our way of thinking. So recognize what is being displayed here
is not an uncertainty as to the year, but a "double date". We've displayed dates
as we found them, double-dated in some cases and not double-dated in others.
England and her possessions adopted the Gregorian Calendar in 1752. The Gregorian Calendar begins the new year on January 1, and also is a number of days out of sync with the Julian Calendar so that, officially, on September 3, 1752 the date was declared to be September 14, 1752 in England and her possessions. This difference in the days is not calculated in the Genealogy reports here, as we're simply reporting what the sources say, and we have not made any "conversion" in the dates -- as you may recognize is done when current calendars report George Washington's birthday.