I guess it depends on quantity? Half an onion is easily just a couple minutes for me--maybe 5-10, at most.

And yes, I know what proper caramelization is, and no, I didn't somehow mess up the time or anything because I keep track of when I finish everything everyday and stick to a strict schedule. I can't eat onions less than fully caramelized without getting severe digestive pain (simply being soft will still burn my stomach), so I'm definitely not cutting corners either.