You can use an external application integrated in RR to do that (GammaControl) available at my downloads page. You simply set the approximate lat/long of your location and it autocalculates the time to switch day/night gamma. There's no built-in gamma auto-switch as of yet.
when i download the gammacontroll where i put?
if i put in thr rr directory the gamma buttons don't switch,
My Home page
Hdd 40 Gb 2,5'
Dvd recorder DL Panasonic
Lilli 619 7' with TS
SoundBalster Mp3+ USB
Holux Gpslim236 usb + external antenna
Remote control with girder