During winter, my chickens stay inside my garage loft area. December thru February. I provide them with 12 hours of electric light, because the window is somewhat insufficient to provide them with sufficient light. The lights do come on and shut off like instantly. It has never been a problem for me. Have done this for over 20 winters.
I have read of different setups others have installed. They use 2 timers, with 2 different size light output. The main light output is obviously quite bright. The 2nd timer is to turn on a dim bulb before the main light shut down. After a duration of time, like 15 minutes, the dim light also turns off. This gives the chickens a little bit of a chance to get to roost, and set for the night.
I have read many posts about adding light to coop. The agreed consensus, is to add light in the morning rather than in the evening. Chickens wake to light inside coop, and start to eat feed inside coop. When daylight arrives, they venture outside into run area, and do what chickens do outdoors. When dusk arrives, they migrate back into coop.
