Yep, I used to do a lot of work for indigenous communities, designing databases and the like. I was amazed to discover that something like a known date of birth was a rarity, especially amongst the Aboriginal elders. No birth certificates. Usually the data was obtained from other family members, purely from memory or based on other events around the same time.

In a lot of cases, only the year was known. If you were lucky, the month as well. We had to strip out all the DATE data types from our database because the validations were constantly failing, or we would have an inordinate number of people born on the 1st of January on a given year. We had to split the date fields out into three separate drop downs, each with a '(unknown)' option so that validation and statistical reporting would be meaningful.

my mom was born in india in the sixties. she didnt get a birth certificate till ~4 years after she was born

she immigrated to canada, and her passport/license/citizen hip in canada reflect the date of the birth certificate.

wrong month, wrong day, wrong year.

funny thing is her cousin was born 3 years after and immigrated to canada, he was born in a major city in india and in a hospital, so had a birth cert at time time of birth.

he is older according to canadian govt issued IDs, yet my mom has pictures of herself holding him when he was a new born.

we celebrate both of my moms birthdates, one on May 3rd (family recollection in relation to historical event) of her real birthday, and July 8th according to her govt issued IDs

While I was in grad school, it was possible for married students to purchase two sets of football tickets. Concerned about scalping, the university one year decided to require a marriage license at the ticket window. It was chaos.

Oh the horror.

> in some past periods, people did not have "identification papers"

You mean last century? People are still alive from then.

Yes, absolutely. I, for example, am one, though I admit I was born only after humanity has visited the Moon. Still, more than 16 years ago.

There's one person left from the previous century too:

https://en.wikipedia.org/wiki/Emma_Morano

Well, she is the last one born in 1800s. There might still be living people born in the year 1900, which is also XIX century.

Shouldn't "previous century" be 1900-1999?