I don't agree that light is best at different times of day, it's simply different. You can adjust to the light by adjusting exposure & development, or by looking for better light. For example light at noon is not the greatest for portraits, but take the subject to a shaded area and boom, you have changed the light completely.

The light under a baseball hat is not the same light that hits the top of the baseball hat, if you know what I mean.

I can't explain this too well, sorry. It's just a matter of looking at the light, and thinking in terms of what the light will do (flat light = flat print, etc...).