Comment by sam_lowry_
2 days ago
Belgian National Number is your birth date, then an increment from 1 to 999 for every baby born that day, then a base-97 checksum.
2 days ago
Belgian National Number is your birth date, then an increment from 1 to 999 for every baby born that day, then a base-97 checksum.
Not sure if still the case: odd numbers for males and even numbers for females.
This also means a person’s Belgian RRN can change.
Yep, but they do not change on sex change, IIRC.
I wrote a system for a medical lab decades ago and IIRC I did actually have to change some RRN's manually. It's been a while so I'm not 100% sure, but I do think the changes were due to switching gender.
Are there never more than 1k babies born in a day?
With a population of 12M and life expectancy of 80 years (give or take), probably not, as that needs ~400 newborns a day to maintain, and the birth rate is probably well below that, like in most Western countries.
Back-of-the-napkin math supports that, but baby births aren’t uniformly distributed. Well, anyway, I’m sure they thought about it. Thanks for explaining how I got my Belgian ID number!