
Show HN: Wake Up Time – A calculator that helps you wake up refreshed - dotspencer
https://wakeupti.me
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gkbrk
The Android app "Sleep as Android" [1][2] is awesome as well. Uses ultrasound
to detect your movement/breathing and wakes you up at the correct part of the
sleep cycle, even if your calculation goes wrong due to falling asleep later.

[1]: [https://sleep.urbandroid.org/](https://sleep.urbandroid.org/)

[2]:
[https://play.google.com/store/apps/details?id=com.urbandroid...](https://play.google.com/store/apps/details?id=com.urbandroid.sleep&hl=en_US)

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dotspencer
I always thought that 8 hours was the best amount of time to sleep but so
often I'd still wake up feeling groggy and tired.

Sometimes I'd go to bed at 1AM and wake up around 7AM and feel so refreshed
and awake. What's up with that? Turns out, getting 8+ hours of sleep is less
important than waking up aligned with your body's sleep cycles, which for most
people is every 90 minutes.

I created Wake Up Time so I could quickly see the best wake up times before
setting my alarm each night. Because time math is hard... Especially when
you're tired.

