90night: SleepyTime Calculator helps you pick the right wake or going to bed time

Martin Brinkmann
Feb 14, 2014
Updated • Feb 14, 2014
Apps, Google Android

I try to go to bed at the same time every night. While that works fine most of the time, it sometimes does not because of work or other things that get into the way.

Yesterday for instance, I had to stay up two hours longer than usual due to Ghack's server migration. Since I did not want to risk waking up to a non-working site, I had to stay up and monitor the process to react if things went the wrong way.

If you do know how much sleep you need, or want to calculate how much sleep you get, then you can either do the calculation in your mind, or use an application such as 90night: SleepyTime Calculator for Android instead.

The app is compatible with all versions of Android from version 2.3 on.

So how does it work?

When you install the application on your device and start it up, you are taken to the main screen where you can enter the time you plan to go to bed, or the time you want to wake up.

Alternatively, you can select to go to bed right now, which saves you the trouble of selecting the time manually.

The application uses the 12-hour format by default, but that can be changed in the settings it ships with. Once you have set the time, you can make the selection whether you want the app to calculate the wake time or bed time for you.

It displays several options to you on the next screen that highlight how much sleep you get when you select them.

The suggestions range from 1.5 hours to sleep to 9 hours of sleep, with no option to modify the presets. When you make a selection, an alarm is automatically set for you so that you do not have to do so manually.

You can go back at this point in time as well if you do not want to set an alarm. If you have set an alarm by accident, you can delete it again using the notification area or the native clock app that ships with Android.

The alarm will go off at the specified time to wake you up and ensure that you don't oversleep. The settings provide you with an option to enable snooze alarms, which enables you to set multiple alarms in intervals.  Useful if you are a heavy sleeper or just have troubles getting out of bed in the morning.


90night: SleepyTime Calculator is based on the popular Sleepytime web service that you can use to calculate bed times.

The app can help you find a better sleep schedule provided that you follow its lead once you have configured it.


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  1. MNeMiC said on February 14, 2014 at 3:02 pm

    Any iPhone versions of this app?

    1. Anonymous said on March 12, 2014 at 4:44 pm

      OH I SEE

    2. Simon Falck said on February 14, 2014 at 5:57 pm

      There’s a web version, that works fine on iPhone.

  2. BBB said on February 14, 2014 at 2:05 pm

    There are some generalisation faults in this app.

    a cycle is
    1. suggests that if go got to bed at time x you fall asleep at time x. for me it take easily 30min even if i’m tired. But that you can adjust that fairly easy.

    The bigger problem is that is I recall the dream cycle studies well, one first sleeps for 3 two-hours periods and then the cycle period reduces to one hour, and if you sleep even longer it furthers shrinks to 30 – 15 minutes.

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