heating times for bearded dragon

Question
Hi, i have had two bearded dragons for around two years now and was wanting the best for the lizards. I'm concerned that when i have them in there inclosure, that i am not keeping the heat lamp and UV lamp on long enough. should i be turning the heat lamps off in the colder seasons to allow the lizards to hibernate? and how long should i be keeping the lights on for during the day. do the hours alternate depending on the seasons of the year? please help, thank you regard's brad.

Answer
 Personally, I keep the timers set to follow the sun.  It is autumn by you so I would have it set 12 hours on and 12 off, as it gets closer to winter, then 10 hours on and 14 off.  Spring is 12/12, and then summer the opposite of winter.  
 Beardies in captivity will choose what they want to do in winter.  Some sleep hard, some will bask and not eat, and some it will be business as usual all year.
 Their hibernation, called brumation is best described by Dr. Kathryn Tosney:

http://www.bio.miami.edu/ktosney/file/BDbrumate.html