If you have the EVIC instead of the regular OTIS in the overhead console you can change the amount of time easily.

 

This drives me nuts on my new Dodge RAM 1500 (2003). I have gotten used to it, but today I left the head lights on by accident and I came out and they were off and the switch was def. on. So i guess you could always leave it on? (except that one time it doesnt work as it should and ur battery is dead as the guy mentioned)

btw, do your climate control dials light up with your lights on? I think i knocked itloose when I did my head unit maybe, only the ac light lights up.