Sunlight at a low solar angle provides optimal light to set the circadian clock and time cortisol and melatonin rhythms.

“Sunrise time will vary BUT you don’t need to see the sun cross the horizon itself. Just while it’s low in the sky.”

“VIEWING morning sunlight is by far the most powerful anchor for your circadian clock, sleep, mood, etc. so view it as early as you can.”

“Low solar angle sunlight (around sunrise and sunset- and NOT just when the sun is at the horizon), is the optimal stimulus for setting your circadian clock for daytime wakefulness, night time sleep, mood & health.”

“Rather, aim to view the sun rising (the verb) aka low solar angle.”

“But as the sun starts to descend, it triggers those same neurons in your eye that communicate with your circadian clock, but it communicates with a different component or different compartment within the circadian clock... the tool that I'm describing of looking at the sun in the late afternoon and evening... signals to that clock that it's evening time and that sleep is coming.”

“In the evening when you view low solar angle sunlight so in the a the afternoon Setting Sun or evening Setting Sun you do the exact opposite you're phase delaying in the clock ... that's the equivalent of making yourself stay up a little later and wake up a little later”

“These two signals average so that your clock stays stable You Don't Drift meaning you're not waking up earlier every single day or going to sleep later every single day this is why it's important to view low solar angle sunlight in the morning and again in the evening as often as possible”

“look at low solar angle sunlight early in the day what that does is it what call it as phase advances the clock ... you're making it such that you will want to go to bed a little bit earlier and wake up a little bit earlier the next day”

“if you have to pick between low solar angle light earlier later in the day and keep in mind if you miss a day no big deal it's a slow integrative mechanism average ing across the previous two or 3 days but if you miss a day you'll want to get twice as much light in your eyes that next morning the reason it's better to do in the morning as opposed to the evening although both would be to do uh best would be to do both excuse me is that most people are getting some artificial light exposure in the”

“it's really that sunrise and sunset that are critical”

“So these neurons, what they're really looking for, although they don't have a mind of their own, is the sun at what we call low solar angle. The eye and the nervous system don't know anything about sunrises or sunsets. It only knows the quality of light that comes in when the sun is low in the sky. This system evolved so that when the sun is low in the sky, there's a particular contrast between yellows and blues that triggers the activation of these cells.”

“this is why it's important to view low solar angle sunlight in the morning and again in the evening as often as possible and it's done by that readout of those two photo pigments”

“How low solar angle sunlight affects the circadian rhythm”