If I had a preference of when best to shoot photos I would say early morning, just before the sun rises. I feel like the cooler blue tones of the morning tend to create a better range of colors than the sunset time of day, which tends to be warmer and redder. I think this morning shot is a perfect example, especially with the orange and red rock to compliment the cool blue tones in the shadows.
This is another shot I took from White Pocket near the Utah-Arizona border. As you can see the surreal rock formations are quite a sight to behold.