It depends.
What species? A Mellers need a completely different schedule than a veiled. My quads and graciliors need more frequent misting than a Mellers, but don't need it for as long a duration. Also consider the health status of the animal itself. An animal with a health issue will need more humidity. Kidney failure is a leading cause of death of chameleons and kidney failure is caused by chronic or acute dehydration, which suggests that keepers are not providing enough humidity and water.
What is the environment of the cage itself. The same species animals in the same house will have different misting schedules based on how easy it is for the cage to maintain its humidity. The obvious is whether it is glass, screen or three sided with a screen front. Not so obvious is how heavily planted with live plants it is or how humid the ambient air is. Air conditioning and heating will suck the humidity out of the air. The humidity of the air outside the house also affects it.
My misting schedules change a lot depending on my weather.