Dpo is when exactly?

Lauren • 34 expecting baby #4! 💙👶🏻💙👶🏻💙👶🏻💗👶🏻
Ok is your dpo the day past your last "green day" on glow? Or your 33% day during fertile week? 
(I know the app doesn't KNOW when you ovulate but I'm going off of it bc I'm not wasting money on ovulation kits, at least not yet) ;)