

Review sleepyti.me bedtime calculator (my weekend project) - david_shaw
http://sleepyti.me

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chetan51
It's simple and beautiful, but I'm just not sure how much value it has as a
web app. Pretty much, the only real information you're giving to the user is:

* Sleep cycles typically last 90 minutes

* The average adult human takes fourteen minutes to fall asleep

Unless you add some personalization, user-specific memory, or some other
value, it's not gonna be more useful than just a blog post containing the
above two facts.

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hugh3
I'm also rather unconvinced that the 90-minute sleep cycle thing is
particularly accurate for everybody. If your own sleep cycles are just ten
percent off from this value, you're screwed.

Also, after telling it I wanted to be up at 6am, it recommended bedtimes
anywhere between 9pm and 1:30 am. Is it trying to imply that I'd be better off
with four and a half hours worth of sleep than with eight hours, even though
eight hours isn't a multiple of 90 minutes?

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david_shaw
The theory behind it is that, yes, you will wake up more refreshed with three
hours of sleep than four, because if you wake up mid-cycle you will be
terribly groggy (a problem I suffer from fairly often).

The large range of sleep (four times) is designed to matchup with most
peoples' typical length of sleep (six to ten hours).

As far as differences in sleep cycles, you are totally correct. My research
led me to determine that ninety minutes is generally accepted as the total
length of four stages of sleep, but any variance from that will skew the
results. That said, the vast majority of people (supposedly) complete the four
stages of sleep in about 90 minutes.

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SabrinaDent
Actually I like it, and while I wouldn't call it beautiful, I think it has
utility just as it is. I'd consider porting it to an iPhone or Android app,
too - it might find the biggest audience there and more recurring users.

While I don't think there's a huge amount of mileage in personalising it into
a sleep log system, I do think there's some value in _reversing_ it:

It is now 23:27. If you assume it takes me 14 minutes to fall asleep, what are
the optimal time choices I should set my alarm for?

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david_shaw
I like this idea! I originally designed it because I always knew what time I
needed to get up to complete my morning routine and get to work on time, but
it would be cool to customize my alarm (to the nearest 90 minutes) to when I
finally get tired and go to bed. Great idea, and thank you!

