Use of Old Style Julian versus New Style Gregorian dates
In the English-speaking world transition to the Gregorian calendar occurred in 1753. I was told by a Family Search help technician that dates from all documents are displayed exactly as found in the source text, that is even a Julian date, without clarification as to which kind of date it is. This is a violation of general publishing practice, where dates are converted to Gregorian and stated in that form, not necessarily accompanied by the original Julian form.
As an example, the citation at https://familysearch.org/ark:/61903/1:1:JMVY-MZG gives a christening date as 27 Jun 1605. A user will naturally enter this under Vitals, yielding a misleading Julian date in the entry.
Indexers should therefore convert all pre-1753 dates to Gregorian form. Online tools are available for this purpose, such as https://planetcalc.com/7083/