Adult chams will generally take longer to shed and may shed in different areas of the body at times. 4 days does seem a bit long though. I would give him some extra misting sessions to help with the process.
6-7 months is fairly close to being an adult. Veiled's also tend to grow pretty quick. We'll be able to help you out more if you fill out the form below. I wouldn't worry too much about his shedding as long as you're not seeing anything out of the ordinary with his skin. Just give him some extra misting sessions for now and keep watch.
Cage Info:
* Cage Type - What kind of cage are you using? What is the size?
* Lighting - What kind of lighting are you using? How long do you keep the lights on during the day?
* Temperature - What temperature range have you created? Basking spot temp? What is the temperature at night?
* Humidity - What are your humidity levels? How are you creating and maintaining these levels?
* Plants - Are you using live plants? If so, what kind?
* Location - Where is your cage located? Is it near any fans, air vents, or high traffic areas?
Chameleon Info:
* Your Chameleon - The species, sex, and age of your chameleon.
* Feeding - What are you feeding your cham? What amount? What kind of schedule? How are you gut-loading your feeders?
* Supplements - What are you dusting your feeders with and what kind of schedule do you use?
* Watering - What kind of watering technique do you use? Do you see your chameleon drinking?
* Fecal Description - Briefly note colors and consistency from recent droppings.
* History - Any previous information about your cham that might be useful to others when trying to help you.
* Current Problem - The current problem that you are concerned about.
Sometimes the shed stays on a little bit. If you are really concerned, what you can do is gently spray some warm water over his cage to try and "push" the shed off. Usually it will eventually come off by itself.