I believe it, because my sleep habits and general demeanor in the summer versus the winter are vastly different.

I have a sun lamp (I call it my SAD boi lamp) I use during the winter months in the morning and I absolutely notice the benefits of it right away. I feel more energized and in a much better mood. I remember reading somewhere (maybe from the Philips product website) that as little as 15 minutes of sun lamp time is enough to be beneficial, but I leave mine on for about an hour.

The circadian rhythms benefits are absolutely true too. Your body says ok, the sun just rose, so let me set my awake timer countdown now. I would highly recommend it even if you don’t have seasonal affective disorder for the sleep improvement alone. I find it’s much easier to go to bed and after a few days of use, it’s easier to get out of bed as well!

So, article says you need sunlight within an hour of waking up. Sunrise has been about 6 at lately. If I slept until 5am I’d feel terrible. I honestly don’t care how long after I wake up the sun comes up, as long as it comes up for the majority of the day. BUT the amount of time in the afternoon that the suns up matters FAR more to me. I very much prefer DST.

Personally, I do/feel MUCH much better in summer months, mostly because the sun is typically at full strength, and bright. I don’t use artificial lights unless absolutely necessary (they are a migraine trigger for me). BUT, I wake up at about 4am, get out for a run (minimum of 30 minutes) and then start my day.

I wake up feeling a lot better with my blinds open if that counts