Managing system time

The accuracy of the phone's system time is important for all planetarium apps. It is especially important in the case of SkEye since it uses real time object locations for alignment. If the time is wrong by a few minutes the errors add up, sometimes up to several degrees of bearing.

Android doesn't let applications change the system time. There are two choices to the user for setting the system time:

  • Automatically set to network provided time (the mobile carrier network, not the Internet).

    The problem with this is that the network's time may not be accurate or may not even exist in certain parts of the globe.

  • Set to the time manually.

    The problem with this is that the timer may drift over a period of time. So you will have to periodically check and reset the clock.

To check how accurate your system time is you can use a GPS app or the Clock Sync app (former uses GPS time while the other uses the Internet to access the atomic time).

I recommend the Clock Sync app. If you have a rooted phone, this app can automatically sync the system time to the atomic time. Otherwise, you have to manually adjust the time with the aid of prompts from the app.