"Why would you say it isn't mimicking the natural cycle, out of curiosity?" -Olimpia
I am not debating the hours of sunset and sunrise, but a lights on a twelve hour cycle is the closest way to mimick the length of day in Madagascar. My timer is simply set at different times due to my overnight work schedule so the chameleon will be awake at night so I can feed him before leaving. This is what I meant by mimicking the diurnal cycle (length of day):
The natural cycle of Madagascar is very close to a twelve hour cycle from where my chameleon would be considered indigenous. In the nothern hemisphere it's summer while in the southern it's winter. The medium between the two hemispheres is obviously the equator. During winter, we will see less daylight because of the earth's orbit around the sun. The equator will always see the same amount of daylight due to the tilt of the earth's axis. The axis is what makes the difference in daylight (seasons) between the northern and southern hemispheres. Thus, the sun will always be in a twelve hour cycle along the equator.
The equator remains, in essence, the same season (temperature) year round due to the heat from the sun throughout the day; the span between sunset and sunrise is the cooling period [the sun is much like the heating cycle of a house: the longer the cycles the hotter the house (earth) will be. Of course, the opposite is also true: the shorter the heating cycles, the cooler the house (earth)].
The largest difference Madagascar experiences is on the southern tip of the island where the length of the day only changes by a maximum of one hour. The northern tip of the island would be where my panther chameleon would call home, seeing as it is a morph and a cross between four different species which all reside on the northern tip of the island. The change in the length of the day there is only 30-45 minutes difference. Check it out on
www.timeanddate.com. There is a sun and moon calculator where you can find the changes in the length of the day at any location on the globe.
Just saying that if you're concerned with eliminating inconsistencies in the circadian rhythm (sleep pattern) of your panther chameleon, an 11 1/4 to 12 hour cycle is the way to go.