Getting the application or the OS's running time in React Native

Question

Is there a way to get the elapsed running time of an application in React Native?

If possible to get some form of ticks which is not related to the device's time & date.

Pseudo code:

const ticks = Application.getTicks();
console.log(ticks);

While changing the device's date & time will not affect the returned ticks.

Why not just keep track of the current`dateTIme` on start up? Then when you want to check subtract the current `datetime` to the one on start up? — Train, Aug 05 '18 at 23:12
@OrthoHomeDefense We're trying to prevent users from tampering with the date and time of the device to effect their check in time while the device is offline — Guy, Aug 05 '18 at 23:51
Getting the current `dateTime` in `JavaScript` does not get the device `dateTime` using `new Date()` does not get the device time. Am I just not understanding you correctly? — Train, Aug 06 '18 at 00:00
In React Native it does get the device time as far as I know. For instance: https://stackoverflow.com/questions/41294576/react-native-show-current-time-and-update-the-seconds-in-real-time — Guy, Aug 06 '18 at 00:58

score 1 · Accepted Answer · answered Aug 06 '18 at 00:34

I have found the answer on the following Gist.

To utilize it, I've built a simple module that returns the number of seconds since the OS was started.

The usage is as following:

import RelativeTime from 'react-native-relative-time';

and:

RelativeTime.getRelativeTime()
    .then(ticks => console.log(ticks);

It returns the number of seconds since the OS started:

Restarting the Android simulator resets the value returned (as expected)
Restaring the iOS simulator seems to keep the value. Probably means the value which is returned is the Mac's uptime.
Changing the device's time does not change the value returned (as expected)

since in iOS you use time(&now) to calculate the elapsed time, doesn't that compromise the uptime? if a user changes time settings it will return a false value — daydr3amer, Aug 19 '20 at 10:14

1 Answers1