The best time is early in the morning, before it gets hot and in the evening when the shadows start getting long and it starts cooling down. One thing to watch is atmospheric pressure. When the pressure is high carp will sometimes post up right on the bank, halfway out of the water. When the pressure is low they move further out. Best time of year is when the cotton wood seeds are all over the place, but carp will still bite pretty good from late spring into fall. Use corn or live crawdads on a small treble hook and fish the bottom.