Photographers call it the golden hour or the magic hour. It's that time when the sun is near the horizon, or just below, and the character of the natural/available light changes. The light quality is best when the sun is 6-7 degrees above the horizon, and the effect ends when the sun is 6-7 degrees below the horizon. It's not always a fixed time, because it depends on the season and the distance you are from the equator.
Photographers and cinematographers often seek out the golden hour; it can add a striking tone to your photographs.
Now, the iPhone comes to the rescue. I've recently been using 2 apps that calculate the golden hour based on your location. One of the apps is pretty simple. The other actually shows you where the sun will be
