Someone said to me, "Adrian is dating Michelle"
But actually what he meant was that they were going to have the first date in the near future. Can I state that I am dating someone if we never did it before, just because its a sure thing to happen?
I would take this to mean that Adrian and Michelle are engaged in the kind of relationship that includes going on dates. Whether or not they have actually gone on an actual date at the time of utterance seems largely irrelevant to me.
So two people may have mutually agreed to be dating each other, and await their first date this coming Saturday night- I would still say they are "dating".
It is one of those slippery verbs that can mean several closely related things at the same time.