The 'golden hour' is already a term to describe the first and last hour of sunlight in a day, a favorite of photographers.<p>Popups kicked in before I could read more, but this is a different, unrelated, misnamed 'golden hour'.
For those of you who don't like paywalls (like me) an unlocked version of the research is here <a href="https://www.bhf.org.uk/informationsupport/heart-matters-magazine/news/behind-the-headlines/sleep-time-and-heart-disease" rel="nofollow">https://www.bhf.org.uk/informationsupport/heart-matters-maga...</a><p>And if you want a deep dive, the original article (including a LOT of details about the research) is here <a href="https://academic.oup.com/ehjdh/article/2/4/658/6423198" rel="nofollow">https://academic.oup.com/ehjdh/article/2/4/658/6423198</a>
"Open your curtains as soon as you wake up" - I've recently moved to a place where my bedroom window has no curtains and my sleep quality has improved drastically. Lots of other variables, but intuitively it makes sense to me that morning light would help stop the sleep cycle slipping later, thus keeping me reliably ready for sleep at the end of the day.