I've seen this question a few times, and have often thought about setting the lights to mimic what the chameleons would be exposed to naturally.
I did some research on the web, and compiled the table below. It shows the amount of daylight hours (from sunrise to sunset) in the capitals of Madagascar (where most species are from) and Yemen (where the Veiled species orginates) on the 15th of each month of the year. (I'm not sure how to post tables to the forum: sorry if the alignment of the columns is a bit off)
This might serve as a guide as to how much light to provide to your chameleons throughout the year. As you can see, 12hrs is quite a good approximation. And perhaps this can be adjusted to give an hour's extra light in summer, and an hour less in winter.
hmmmm, this might explain why my chams have always "slowed" down a little in the winter. I never thought about tweaking his light hours down, I bet the little guy is just too tired from all the light.
Taking the hours down can give you plants a chance to rest. A plant such a hibiscus will not usually flower under twelve. If it does they will be very underdeveloped and not to straining on the plant.
Nice touch Tygerr. I love when people use information like that.
Well let me start by saying this is a friend of mine that has been doing that he use a metal halide light I believe (could be mercury vapor). He works the lighting up to 14 hours in the summer and down to 10ish in the winter. The plants seems to stay semi dorminant during the winter. Producing smaller weaker buds as the lighting goes down. As the timing goes up the buds get bigger. I personally do not like high intensity discharge lighting. A specific incadescent plant growing bulb in place of the basking bulb would probably be sufficient to accomplish this. I read something on Hibisicus the other day but could not find it for referance on this post. It said that they required a certain wave length that only a more specialized light bulb could reproduce. Hibisicus do better in general with some down time in the year so they do not burn themselves out.
As with alot of hydroponics growers 12/12 keeps flowering plants in the vegation state. 18/6 is perfered to make the best buds. I guess with that, this could be alot of the reason chameleon owners that use thes plants run into problems with keeping them healthy. I do not know if ClmrJ used actual sunsetting (and sunrise) or visible light in that schedule
The juvenilles can take pretty signifigant drops to. I would not really worry about it. You are warm blooded so it is doubtful that you would keep your house low enough to really be concerned with it. Alot of owners draw the line at 50 degrees. If my house where 50 I would be shivering like crazy (I do not do good in cool weather).
You always hear of these guys overheating. If you look up weather records you will find that Aden in Yemen has the second highest recorded temperature on Earth at 139 degrees second only to a spot that hit 141 in the Sahara. Yemen actually broke it but they deemed some results unacceptable as they where not weather stations. With the humidity tacked on that puts what the temperature feels like at about 155. Talk about a crappy day.