How long does a couple need to date before they get engaged?

I was watching a show the other night a woman was explaining that her and her husband (now ex husband) got engaged after 4 months if dating. To me that sounds ludicrous so it got me thinking what is the appropriate time a couple should be together before jumping in to that huge decision? What’s your view on the topic?

disclaimer this has nothing to do with my relationship though I’ve been asking a lot of relationship questions recently