Recently I spent an afternoon at the SOUTHERN CALIFORNIA GENEALOGICAL SOCIETY library. As it often goes, I came in looking to break through a brick wall on one line, but while going through books I found one that mentioned that Poles often named their children for the day they were born or baptized. There was a good list and so I decided to compare the names of some Polish ancestors with the Polish (or Eastern-Central European) saints lists.
To my surprise there was a true connection (birthdate and saints day) of 7 out of 10 of the people I chose. Now, does that mean they were simply named for the saint of the day when they were baptised rather than born?
Now, to this day in Poland people often celebrate their saints day as their birthday.
HERE IS WHERE IT GETS TRICKY: YOUR IMMIGRANT POLISH ANCESTORS MAY HAVE USED THEIR SAINTS DAY AS THEIR OFFICIAL BIRTHDAY on U.S. paperwork/records. It is possible that this will correlate with their baptismal in Poland but maybe not.
According to the book I read, POLISH ROOTS by Rosemary Chorzempa, parents sometimes picked a name within up to a three week period surrounding the actual birth.
Because 3 out of the 10 names I checked did not correlate with a saint day, I think this is possibly the name of a family member OR THEIR BAPTISM sponsor.
I'm linking to the Rootsweb list of Polish Saints Names; REMEMBER THAT THESE CATHOLIC CALENDER DATES MAY HAVE CHANGED OVER TIME and that you may be able to determine ethnicity within Poland or other countries by linking the name and the saint!
What this reinforced to me also is the Catholicism of this family.