Yet other teens do go on dates with each other that are somewhat more formal where one member of the couple picks up the other one in a car for an afternoon or evening together that has been pre-planned.
My 12 year old daughter has asked me when she can start dating.
Let's just say that I was sort of a goody two shoes and didn't want to upset my parents. I am now a mother of a 12 year old daughter and a 10 year old son.
I think that for dating where one person is picking the other up, 16 is obvious because that is the driving age.
But my personal opinion is that if they want to go to a movie or other activity together, and a parent will drop them off and pick them up from that activity, I think 13 or 14 is perfectly Ok.
Make sure to act interested but not too interested in your teen's dating life with the hope that they will open up to you if they run into difficulties. Friends are marginally ok but not romance of any sort. If they don't experiment, they won't know how a relationship works in the real world.