I have 4 relatives for whom I have both the original European birth record
from Nezhin Ukraine and a date of birth on an official U.S. record. In twocases, the U.S. date of birth seems fictional in that it is unrelated to
either the Julian or Gregorian original version. In the other two cases,
the U.S. date seems to be a (faulty) attempt to use the Gregorian date, being
4 and 5 days later than the Gregorian date.
Too small a sample to be significant.
San Diego CA U.S.A.