How do you know when you have officially dated?

So my friend told me on face book that he liked me. He liked me because I was an optimist person. Today, he talked to me and he said he was going to take his time telling me something. He was going to go attend a training session in Texas to become a health care specialist in the military meaning he will get deployed. So he promised me before that happens, he will take me out to dinner. He didnt ask me if I wanted to go out with him...does this mean that we are not dating? Does this mean that he just has respect for me because I am his friend? Or are we already dating? o.O