Reason Birthdates Are Sometimes Differant
Birthdates are often wrong
Prior to around 1900, few people in what is now southern Croatia (then Austria) knew their exact birthdates. It was not a custom to know or celebrate one's birthday. When authorities asked, the person would often take a guess or make up a date, and stick to it for the rest of their lives. This leads to many incorrect birthdates in U.S. death certificates and tombstones. When writing for, or looking for, church records in Croatia, it's always best to qualify your identifying information by saying something like "to the best of our knowledge, he was born on xxx." An educated guess would be that around 50-60% of all birthdays as shown in U.S. documents of people who were born in what is now Croatia are wrong -- maybe higher.