When you notice you "shedding", are you just reading a book or something and hairs fall in front of you, or are you running your hand through your hair over the sink to see if you are shedding?
I ask because I noticed the same thing, but I think I figured it out. You take a shower in the morning, and those hairs that are loose and about to shed come out then. You get out, dry off, style your hair, and you might notice a few more, but the majority came out while shampooing 5 minutes ago.
Then you go about your day, and some other hairs might come loose, about to shed. But unless you agitate them, they aren't going to jump from your head onto the ground. They will likely stick to other hairs on your head, until you get home, and either 1) showe in the evening, or 2) shake your head over the sink.
Make sense? Not saying this is why. Perhaps more hairs are shed in the evening than in the morning.