[coldsmoke]

Actually, it already is a problem. According to this article, around 2,500 people have been assigned a personal number which differs from their birthdate. [1]

The last digit is just a checksum digit, so we're left with 3 digits per day. But that still would give some leeway for each day. The problem seems to be that some immigrants have been assigned a default birth date (Jan 1 and Jul 1) as their exact birth date is unknown.

Another issue which is not mentioned in the article is that we're only using two digits to encode the year (i.e. YYMMDD-XXXX), which causes problems now that many live to be 100+ years. Most banks and other places now requires you to enter a four digit year, even though that technically is incorrect. The correct way to annotate that someone is over a hundred years old is that the dash changes to a plus sign (i.e. YYMMDD+XXXX), although I've never seen that implemented anywhere.

[1] https://translate.google.com/translate?sl=sv&tl=en&js=y&prev...