I think you will get a lot of different answers concerning fresh or aged. Not certain about time of day collection.
I have particularly difficult scalp with dandruff and a lot of itch. I used aged urine for a while which was recommended by many (books, and sites) and found that the odor didn't rinse out even if I shampooed a couple of times so I quit using it at all. Then a couple of months ago I began using fresh - before a shower is a convenient time to gather it, and I get great benefits for my scalp. I also use it on my face at that time as an after-shave while massaging it in. I don't go beyond that, but have found that this routine is easy, beneficial, and something that I'll continue to do.