This excellent article tells us the exact opposite of what the media and dermatological community would have us believe: The best time for safe sunlight exposure is at midday because at that time, the sunlight is more direct, making possible more vitamin D production by the skin.
In the rush by dermatologists and sunscreen companies to demonize sunlight exposure as the universal cause of skin cancers, there has been a total disregard for another factor that strongly protects against or strongly promotes skin damage. That factor is what we eat.
Research from Norway indicates that people who use tanning beds, and those who spend the most time in the sunlight, have better health due to the increased vitamin D levels produced by such habits. This is the type of article that must drive the sunscare industry crazy.