> Sleeping after sunrise counts for zero - it is useless.

I don't know about some people, but for me this is practically the silliest thing I've ever heard.

I need 8 hrs of sleep period, and the time of day has zero effect on my alertness. It can be 9pm-5am or 3am-12pm, it's exactly the same.

But if I get only 6 hrs of sleep? I'm miserable.

I can't even begin to imagine where the idea that the hour of the day matters would have come from.

And just think of nighttime workers. Obviously their daytime sleep counts...

> I can't even begin to imagine where the idea that the hour of the day matters would have come from.

The idea that sleeping in is lazy and self-indulgent while rising at dawn is virtuously ascetic?

> I can't even begin to imagine where the idea that the hour of the day matters would have come from.

Many bodily functions such as hormone production are affected by your circadian rhythm [1]. Ambient light also seems to have an effect on quality of sleep.

[1] https://www.nigms.nih.gov/Education/Pages/Factsheet_Circadia...

> I need 8 hrs of sleep period, and the time of day has zero effect on my alertness.

It matters a lot, especially if it’s 5 AM - 1 PM. In high school, I was an RF technician, testing the rollout of LTE in my area. We had to conduct drive tests at night, due to traffic concerns. Working at night and sleeping during the day seriously disrupts your natural circadian rhythm. The only reason we as humans don’t sleep immediately after sunset is due to the invention of artificial light.

I sleep during the day and work nights, so yeah, that's complete crap.

> And just think of nighttime workers. Obviously their daytime sleep counts...

I think the quote is more an aphorism than rigorous guide. The framers of the quote probably didn’t anticipate the night shift ;)

It's interesting to consider that the 9-5 workday is a very modern innovation, especially considering how long Ayurveda has been around.

> In the traditional medicine system of India (Ayurveda)

“Ayurveda medicine is considered pseudoscientific.”

https://en.m.wikipedia.org/wiki/Ayurveda

You skipped the following sentence in your quote: "Other researchers consider it a protoscience, or trans-science system instead."

Early thought systems evolved from hundreds of generations of folk wisdom. There are significant enough gaps in modern scientific understanding that to discount these systems is foolish.

Note that the current discussion is set in such a gap.

From the god of the gaps to the pseudoscience of the gaps. The same 5 old tricks to justify superstition and folk belief.

I'd expect most traditional medicines to be considered pseudoscientic if they predate the invention of the scientific method.

That said, I'd take science-driven modern medicine over weird herbs and rhino horns any day of the week.

If you go to sleep at 4pm and wake up at midnight, does that count as 16 hours of sleep or zero? This system suffers from the reverse Gremlins problem.

Sounds like it's not really worth sleeping during summer above the Arctic Circle, then.

My grandparents are farmers in part of Northern Europe where currently it’s dark from 11pm - 3am (it’s never truly dark though, and if you look North in the middle of the night it is distinctly brighter). Their sleeping patterns do strongly follow that of the sun, in the winter they sleep more and in the summer they sleep a lot less.

For the work they do this is good though, in the summer there are a lot more things to do, whereas in winter when it’s -20c and the ground is covered in snow, there isn’t very much to do.

In a way I think they have it better than me, trying to go to sleep when it’s still a bright sunny day outside just feels weird.

Or it is possible that humans are maladapted to living in the artic circle.

Maybe by extension it’s not really worth living there ;)

Naps in the day have repeatedly been shown to be helpful and have positive health benefits. I’d say this anecdote is just like a lot of anecdotes passed down by humans and doesn’t match science.

The anecdote does, in some ways, match science: hormones in the body operate on a schedule that is derived from specific frequencies of ambient light, and therefore ultimately the position of the sun.

But there are definitely people who sleep right in the middle of the day, eg siestas in sunny places.

can confirm. taking my nap now, in fact!

If you follow the "normal" schedule of sleeping (i.e. you don't work nights or something), then this probably has more to do with the deeper stages of sleep being more common at the beginning of the sleeping session and REM sleep more common as sleep duration continues.

As a person who induces lucid dreams as a hobby, I sometimes manage to make use of those long lazy mornings on weekends to lucid dream. I've found it's very difficult to have a lucid dream in the first two or three sleep cycles. After that, it's much easier because the REM stage of sleep is longer. Not that I've found that having lucid dreams is easy, I get one day like that every month or two and a spontaneous one here or there in between.

My problem with ayurveda and other traditional stuff is people not realizing they were not your popular paracetamol tablets you could gulp down and be effective. These were wholesome lifestyles. So cherry picking parts may just not be effective for most people and gives traditional stuff a bad name.

I have benefitted immensely from yoga and parts of ayurveda and I laugh at people who dismiss them but I don't like them being cherry picked and tested which diminishes trust in them

Wait - what? You like parts of them but you don’t like people who like parts of them?