That really depends on how much of an infection there is, sort of like gangrene.
If the wounds are life threatening, then it can be less than 20 Astlan hours (i.e. a day) before they get “hungry” In fact, it could be within hours, if the wound would have killed them within a few hours, it can, in theory, be that fast. Of course, if it’s bad enough to kill them, then it just kills them before they can turn. So it’s sort of a race against death vs disease. However, if the disease takes over before they die, and they get food, (meaning ghoul food or ghoulash) they won’t die.
A single bite? Well, like any infection, it depends on their health/constitution. If the bite is deep/bad and they are sickly, one to two days.
Healthy people? It can take up to a week (10 days), possibly a bit longer if really exceptional.
I would say most people have around half a week (5 days)