Solar time

From Mindaugas B on 2014/12/13 20:12:48 +0000

Hi guys, thanks again for the great work!

I’m considering 2 things:

  1. Stable wake up and go to sleep times contribute greatly to sleep quality. SleepAsAndroid already does a fantastic job at helping achieve this.
  2. It is beneficial to synchronize our sleep cycle with sun cycle, as it is the most natural “clock”, to which our body is related in many ways.

Currently used timezone or “wall” clock in our phones is not really very good for achieving #2 because of:

  1. “Daylight saving” time switching twice a year,
  2. Time zone offset from solar time is different in various locations. That is particularly important when travelling, for example if you have set your alarm clock at 7:00 - this can mean quite different things in various parts of China :slight_smile:

It would be very nice to be able to select WHICH TIME I want to use for wake-up alarms and go-to-bed notifications:

  1. Clock time (current functionality)
  2. My location’s solar time (
    2.2. Apparent/true solar time,
    2.3. Mean solar time. (Not sure which of these is better for the body, probably it’s better to have both and experiment).

Technically, calculation of apparent solar time should not be very difficult, simplest example would look like this:

  1. Get current location coordinates,
  2. Calculate sunrise and sunset for given location,
  3. Calculate solar noon time: solar_noon = sunrise_time + (sunset_time - sunrise_time)/2
  4. Calculate solar time offset from clock noon: sollar_offset = solar_noon - “12:00”,
  5. Calculate solar time: sollar_time = clock_time + sollar_offset.
    (this simple calculation, however, does not cover Arctic and Antarctic regions, but I’m sure, it is still possible to do…)

Bottom line: this would allow user to easily set stable and precise sleep schedule throughout the whole year, wherever he may travel! :slight_smile:

P.S. Screen/lockscreen widget displaying both clock time and solar time side-by side also would be more than welcome :slight_smile:

Copied from original feature request:

From Mindaugas B on 2015/05/22 08:08:23 +0000

I've made a simple watchface for Pebble smartwatch called "Solar watch", which addresses some of these requirements. It can be found in Pebble app store (free) or

From Štefan ĎuĎo Čech on 2015/05/15 23:23:30 +0000

totally vote 4 this

From Josh on 2015/03/15 23:38:56 +0000

I agree with Kenneth. The option to have my alarm set to go off during my local sunrise would be amazing. Or even better allow me to set an alarm for x minutes before sunrise so I can bike to my favorite place to watch the sun rise !

From Diogo Oliveira on 2015/02/09 13:36:24 +0000

Amazing suggestion, and well described. I would gladly start using it. And I agree with Kenneth: something as simple as "auto alarm based on sunrise" would suffice for me. "Twilight" app does this calculation quite well.

From Kenneth P on 2015/01/07 16:15:38 +0000

This would be fantastic-- even something as simple as "set alarm to local sunrise" would be really helpful.