You may notice when dealing older vital records that you will see a date on one with a 10 or 11 day difference (depending on leap year) from the other, a 9 month difference or a double year like 1742/3 or 1749/50. This may be because it is a Quaker record and the conversion from the Julian calendar to the Gregorian in 1752. To make matters more confusing if the Quaker's started their year in March. Their new year was March 25th and ours is the 1st day of January, So when dealing with this first check to see if the record is pre 1752 and if it is a church record good chance it could be Quaker,
The old style Quaker dates pre-1752 will look like this : 15d 10m 1700. If this date was transcribed by converting a Quaker record you will get a date of Jan, 05,1700 or Jan 15 1700 depending if they dropped the 11 days when converting from Julian to Gregorian. Unfortunately many genealogists have converted incorrectly resulting in a date of Oct 20 1700. Then for dates between Jan 1 and March 24 there appears to be a year difference but this is only because the New Year started March 25th.
*Dates between 1 January and 24 March were sometimes written as “double dates" - such as February 17, 1745/6 (where 1745 was the Julian Year). Some family historians prefer to write Julian dates in this double date format.
Please make sure to use the modern date in the bio because I have noticed that profiles are being duplicated as a result. I think the acceptable way to deal with this is to have the Quaker date as an alternate fact in the bio.