The most I would recommend staying in the same wet diaper is 24 hours before changing if you have a high capacity diaper to wet in that absorbs a lot of pee.
I've once stayed in the same wet diaper for 2 days before when I had a few days off from work and was wearing a very highly absorbent disposable diaper.
The diaper was ABU Super Dry Kids diaper and held up really good for the first day before it started leaking but I still wore the diaper and would sit on the toilet when I needed to pee and pee in the diaper and let the pee leak out of the diaper and into the toilet to avoid a mess.
The wet diaper felt very good and I masturbated in it a lot as well.
But after 2 days I changed out of the wet diaper before going to bed that night because I was starting to get a rash and the pee was starting to turn to ammonia.
So I would really recommend not going any longer than 10 to 24 hours before changing a wet diaper.
I now wear diapers all the time and use them for both pee and poop and I will change now after 3 to 4 hours when the diaper gets wet enough to change.
I can now afford to buy diapers for 24/7 wearing and have enough diapers to change into so I change more often now.