In summer here in the UK I lie in the sun without sunscreen for 20 minutes a day (I do not burn) and that has a huge effect on my mood. There is a lot of research on that. It lso helps vit D levels, immunity and the ilke. It is why people are better of gardening and walking and swimming in sun and outside rather than in gyms. It is very hard though for those of us with long fairly dark winters. My SAD lamp does not have the same effect.

I would certanily recommend sunshine on as much skin as you can bare every day in summer unless you are somewhere like Saudi and would burn in a second.

There is a big debate about skin cancer v advantages of some sun without sunscreen. I come down on the latter side.