As if that were not complicated and confusing enough, the New Style calendar also eliminated ten days which had accumulated in excess and began compensating with leap years. Pope Gregory XIII began the change to the New Style calendar in 1582, but many countries did not adopt it immediately. Scotland adopted it in 1600, but England did not adopt it until 1752, by which time there were eleven days in excess. Many in the colonies did not adopt the system until later. England adopted the calendar in September 1752, at which time Wednesday, 2 Sep 1752, was followed by Thursday, 14 Sep 1752, and 1753 began on January 1st. Thus, a date that was recorded in a record before that time as 10 Feb 1750 would actually have occurred on the date that would now be 22 Feb 1751. If one were correcting that date in a modern publication, the proper way to record it would be 10/22 Feb 1750/1, meaning that the first numbers are those that show in the original records and that the second numbers would be the ones used in the New Calendar. That can be very confusing when interpreting dates of that period. It is possible that a document recorded in two places within a short time period might have two different dates recorded, which in turn could make it appear that two separate actions had occurred. To be absolutely sure of how the recorded dates compare to the present calendar, one would have to know when the Gregorian calendar was adopted in each place. Details of that change are available in the Wikipedia on the internet, and a good simple explanation is on pages 17-18 of How to Trace Your Family Tree by the American Genealogical Research Institute Staff, published in 1973 by Main Street Books.,. Most writers correct only the year, because the most critical days are the ones from January 1st to March 24th. To avoid too much confusion, I usually indicate when I think that the year given in records refers to a later year, but I usually will not try to correct the day of the month, unless is seems very pertinent. It is hard enough to interpret original records, but it can be even more confused by the interpretations of other researchers and authors. Sometimes an author has quoted an original record but changed the date to the New Style without indicating so. Not knowing that, a subsequent researcher might assume that the date was transcribed accurately and then modify the date again. Such actions can ultimately result in a date being erroneously reported as being two or three years different from the original date. If an exact date is very important to someone, that person will have to find the original record to see what date is recorded, find out when that area adopted the New Calendar, and then modify the date accordingly.
However, further confusion can occur when a transaction happened before the calendar change and was recorded after the calendar change. If the court clerk recorded the earlier date, it is not possible to know if the earlier date was adjust for the calendar change or not.