Possibly a new feature on someones profile. The ability to hide the year should be toggled to hide ones age if they’re especially young and don’t want predators lol.

You’ll only be able to set your birthday in options once. On your birthday you will receive an EC or some sort of gift, maybe a birthday hat. A new birthday hat could be created each year; EX: A 2018 birthday hat, a 2019 birthday hat, etc..

Optionally on someones birthday they could have a colorful glow or aurora around them, just an indicator to show one’s birthday.