So, as a basic answer, I have seen chameleons turn in early before lights out during certain times of the year. There could be many reasons, but yes the temperature in a room or lighting from outside can influence it. As for another thing to consider, if you have recently had a time change due to Daylight Savings Time, your own behavior may be different and can have an effect on your animals. You can be feeding at a different time or just simply have lights on at different times of the day. Tough to tell. I would like to see a picture of the chameleon and it's enclosure to see if there is anything else going on here, and yes, If you cut and paste the Help Form into a response here in this thread it can also be very beneficial. The more details you can give the better. For example, give brands of lights and wattages. Types of feeders and supplements, etc...