When shooting outdoors, I would usually suggest times, either early in the morning, from 7 - 11 am tops, or in the evening, from 4pm onwards, to my clients.

For one reason, it is usually not as hot during those times, and the sunlight is usually gorgeous, with lots of clouds as natural diffusers hence I would get beautiful effects on my photographs.

At noon, the sun is usually right up on top of our heads, so I would usually end up with cringing people on my photographs, and dark and obvious shadows underneath their eyes, which obviously is not the effect that I'm trying to reach.

However, even at those suggested times, it is imperative that you wait or try for the exact moment for your intended effect. That is, if you intend to use absolutely natural light, without any artificial light assistance.

The photos below would demonstrate my points, which is to wait for the right 'light'ing moment. These were taken without the assistance of any artificial lights, in a duration of about 5 minutes

acceptable natural light, nice pose, but not enough zing!

a bit dark, the clouds were roving right on top of the subjects at the time, but I love the pose. you can fire some fill flash if you like

beautiful golden light, absolutely no artificial light, not even a reflector. the trick is to wait for the right moment