When is Google's birthday? Surely Google knows. You do know, right, Google?

Google is old enough to drink, buy cigarettes and vote in the UK. But does it know its date of birth?

What's that Google? It's your 18th birthday today? Happy birthday Google! You're now old enough to drink in Britain. Though the existence of Google Plus suggests you've been quietly breaking that law for a while now.

Sorry to nitpick though, but are you sure it's your birthday? Only, there's been some confusion over that in the past. Right now, on 27 September, you have one of your merry "Google doodles" up on your homepage wishing yourself a happy birthday (also, Google, that's a little sad? Are you OK? Normally we rely on our friends to wish us a happy birthday rather than buying our own cards).