Does ANYBODY EVER provide an accurate response to a question like that (except when there's reason to believe they can detect it and do something to your detriment if you lie)? If so, why? Anybody who asks deserves to be chaffed into oblivion with garbage data. Especially, who would be dumb enough to admit to being under 18, or, worse, under 13? An 8 year old should see the obvious reasons not to do that. A bright 6…
My "birthday" is January 1, 1970 (an homage to unix) for any database/system inappropriately asking. This way they don't have my data to leak or abuse, but I still know what I specified if I'm asked to verify it.
I don't expect there's any reason for them to divide by a datetime...but one can hope that some ad server somewhere has crashed as a result.
My go-to birthday has always been January 1st of the year I was actually born. That way it doesn't raise any eyebrows if I want to convert something to a real account or interact with real people, but it fails verification if they mishandle my credentials.
That's worked great, except that one time when I inadvertently booked a flight on united.com (who should have my actual birthday, with whom I'd flown internationally several times before) with a session token or something set by a random travel search engine to whom I had given my fake January 1st birthday and then (I thought) abandoned before picking a different flight. Customs had pointed questions about the authenticity of my passport and driver's license, because their system showed that my documents should be different and they couldn't tell me why... They eventually let me back into the country, but that was not fun.