I feed my coral after the lights go off or before they come on. The polyps are generally more extended during these times. The fish are obvisouly fed during the day, so I guess the corals are also fed then.
Some species only feed at night or if you provide a significant feeding stimulus to elicit a reponse during daylight hours. I for one target fed "after hours" so my Trachyphyllia and Tubastrea get enough to eat.
