Whats the oldest an 18 year old should date?

This rule states that by dividing your own age by two and then adding seven you can find the socially acceptable minimum age of anyone you want to date. So if youre a 24-year-old, you can feel free to be with anyone who is at least 19 (12 + 7) but not someone who is 18.

Is it okay for a 24 year old to date a 17 year old?

They can date, but the 17-year-old is a minor, so it would be statutory rape if they have a sexual relationship. If they can both wait until the teen is 18 before they consider sex, then itd be okay But, if they dont, the 24-year od would be breaking the law.