I had read somewhere a while ago, that someone suggested. Turning the light on and feed 30mins. later as this gives the fish time to adjust to the light. Then you can feed them 30mins. before thier light gets shut off for the night. Not sure if timing really matters, but that's just what I found a few months ago.
My cardinal tetras take a good 30 minutes to wake up! If I feed the fish right after turning on the lights, the cardinals totally miss out. First thing in the morning, they're all separated out from their school, at the bottom of the tank, pale and barely moving; 30 minutes later and they've regrouped, got their color back and are ready to eat.
I do morning (from 3 seconds to 30 minutes after the light comes on, according to what's going on with ME), & at night around 30 minutes before the lights go off.
I feed at the end of the day...generally 30-45 mins before lights out. I like to watch, as it is the best time to see everyone...even the shy ones. Everyone likes to eat! And if not then something is probably wrong.
Then lights go out and I can drop my waffers for the bottom guys.