When is it dating?

Okay, I'm actually dating someone but I'm not from the U.S. so I don't really know the norms here. So when is it considered dating when two people have been seeing each other for a while now? Some people say it's not unless if they talk about it but what if you go to their family events and birthdays and see each other couple times a week not like a hook up? Is it still not considered dating?