SSA assumes the Julian calendar was used and converts the date to the Gregorian calendar
date if a document (other than a Roman Catholic record) was issued or recorded in
Eastern Europe at the time the Julian calendar was used (see GN 00307.180D.).
SSA does not assume all documents or records made after the dates in GN 00307.180D. used the Gregorian calendar since some registrars continued to use the old calendar.
SSA assumes records issued in countries not listed in GN 00307.180D. show Gregorian dates.