Marstime lets you view time, set alarms, timer and stopwatch for planet Earth and Mars, set time to any timezone, Sol or Earthreal time, Military or Standard time and set the display readout from all information being displayed down to just telling you what hour it is.
Useful features include 6 alarms for both planets, a timer and stopwatch accurate to 1/60 of a second for both planets. Even if you shut your device off it will keep track of everything you have set.
When Started earth time will automatically be set and sync to your timezone, then syncs mars time based on it's discovery date of December 29, 1873. If constantly ran, Marstime should be accurate for about 21,000 earth years!
If you are too far from earth for a connection to the time data server or internet, and if your device is shut down after losing service and re booted at a later time Marstime's time will default to the last known time recorded by the device, and if you know the amount of time lapse from shutdown to reboot you can easily adjust it in the manual set option of the menu.