As a person who is incontinent (bladder only) I generally go through 4-6 diapers a day. I will stay in a wet diaper for several hours as I may wet it several times. It's not economical to change after every wetting and premium high capacity diapers aren't really meant to be changed that often. I find that the diaper I put on before leaving for work in the morning will last me until close to lunch time. I'll change it earlier if I feel like I'm getting too close to capacity. Conversely If I'm busy and it's not near capacity I may just wear it for a few more hours, but in generally I try never to wear a diaper for more than 5 hours as I like to let some air hit my skin, clean up with a wipe and refresh a bit.
Most days my schedule is pretty close to this:
730-8AM, put on diaper
12PM, Change
4PM, change
7pm, change
11pm change into bedtime diaper.