Never had to worry about time of day out here. If I find them I can catch them all day long. Over cast days help a little but once I find the places they are for the day getting 30-50 of them is a normal day. The problem is I always get the smaller ones, largest one was only about 1.5 pounds. I have seen larger ones caught mid day but I never get them. Maybe I am fishing out too far or fishing too small a bait.
As for Green ling, I rarely catch ones over 16 inches, longest was probably 20 inches. But there again, I have seen them caught up to 36 inches.
Ling cod, no problem, catch a 4-8 inch kelp green ling, put a couple big hooks in it and throw it out and let it swim. If there is a ling cod around it is fish on. Have seen them fight over them at times. Little cod won't stay long when a 20# one comes out after the bait.