Group dating until 15-17 years, depending on the child.
Dating itself, not until your married!
Mostly though, it depends on what you mean by dating. I think dating means you are in a relationship with someone and are already seriously considering marriage. Therefore, you are dating to enjoy time together.
If that is the definition, than 18 and under really don’t need to be dating.
The real question seems to be, what age can a child have a romantic relationship? And that answer has more to do with “who.” After settling the question of if a child can have a romantic relationship, then it is simplt a matter of how much time they can spend together, alone, unspervised, and why they would be doing that.
FYI, I was in a romantic relationship at a very young age. My parents allowed one or two “alone times” a month. We would get dropped off at the local movie theater for an approved movie, or go out to eat. So I guess to some point, a young person can “date.” As we just liked each other and had no further ability to marry or be serious, I see no reason why this dating should be frequent.
Our relationship grew through group outings, email and the phone. It wasn’t until late highschool that we 1) discerned we were both called to marriage and 2) our parents felt that we could be alone and from there on our it was our responsibility and choice as to how much time to spend together.
If a young teen was begging to go on a date, I would be wondering, why? What do they want to do that they can’t do in front of friends and family? I saw my now fiancee many times a week at age 15. We ate dinner at each other’s homes, went to Mass together, studied together, etc. Why the desparate need to be alone?