don't dose any ammonia if you have occupants.
if your tank is empty, you can just perpetuate the established cycle by adding ammonia, but once you add fish (or shrimp, or any other critter), adding ammonia would be much more harmful then helpful.
I recently cycled a tank (10g), added a juvenile ram, and then waited a week before I added some other fish (clown killies, hasbrosus cories), and didn't notice any ammonia/nitrates. added a few more cories about a week later, and the same.
when I do cycle a tank, I fairly often skip a day or two here and there without any noticeable loss in ability to handle ammonia.
I'm guessing somewhere twixt a couple days to a week at a minimum, possibly longer.