When I was in my late teens I lived with my dad and he did shift work and I could go a whole day without seeing him. I took advantage of that one weekend and spent it in my room online, looking at porn. I did it 9 times that day, but full disclosure, I was edging before I knew what edging was. I think if I'd been trying for quantity over quality I could've doubled that no problem.
For years I was kind of ashamed of that but I've twice since equaled that with a partner - not masturbation but a full on day of sex - so I'm less bothered about the fact I spent a whole day jerking it now I know that, as long as my partner is willing to keep going, I can go that much with the added difficulty of extra exertion and extra pleasure.