This assumes people are putting in their real birthdays, which IMO is a terrible practice to encourage.
I never put in my real birthday. It's just one more datapoint to leak in an inevitable hack and help scammers exploit me.
Just because a website sticks a field on a form, doesn't mean you need to fill it out.
I can think of maybe 1 website I use that has a legitimate use to know this info about me... and a dozen that use my fictious birthday for no other purpose than an excuse to market at me under the shallow guise of a 'Happy Birthday' email.
I never put in my real birthday. It's just one more datapoint to leak in an inevitable hack and help scammers exploit me.
Just because a website sticks a field on a form, doesn't mean you need to fill it out.
I can think of maybe 1 website I use that has a legitimate use to know this info about me... and a dozen that use my fictious birthday for no other purpose than an excuse to market at me under the shallow guise of a 'Happy Birthday' email.