Many Poles whose surnames are the same as the days of the week or months of the year trace their roots back to an ancestor who converted ,and the day or month of that conversion became his surname.
Often these were Polish Jews who accepted Catholicism for whatever reason (belief, marriage, business, politics, coercion, etc.). But it could also apply to Arian, Lutheran, Calvinist, Eastern Orthodox and other religious dissenters.
This is also true of names containing the nawrot~nawrat root (from nawrócić się - to convert) such as Nawrocki, Nawrat (Czech influence), etc. This may have occurred so long ago that today's bearers of such surnames no longer have any inkling of not being of 100% pure Polish ancestry and Catholic tradition.
Merged: Looking for grandfather, Zygmunt Nawrocki from Sieradz
Hello. I am in the UK and am searching for my grandfather Zygmunt Nawrocki. His last known address in poland was 7 Warka Street, Sieradz. CAn anyone help me to find out if he is still at this address??