Question

I have 2 events in my application. I need the time difference between the two of them so I store the time in a sharedpreferences using this line of code :

public static void PutStatus(Context ctx,boolean stat)
{
        if (ctx != null)
        {
        SharedPreferences shr = ctx.getSharedPreferences("test", Context.MODE_WORLD_READABLE);
        shr.edit().putBoolean("SHIFT", stat).commit();
        if (stat) shr.edit().putLong("START_TIME", System.currentTimeMillis()).commit();
        }



}

And then I calculate the difference between the two date and times using this :

SharedPreferences shr = getApplicationContext().getSharedPreferences("test", Context.MODE_WORLD_READABLE);
            long time_stamp = System.currentTimeMillis() -  shr.getLong("START_TIME", 0);
            Date data = new Date(time_stamp);   

The minutes are working great but the hours are 2 hour ahead.

Why is that does it have any connection with timezones ?

Answer 1

The proper way to get a duration with Java is a little bit complicated. You would create it the following way:

import javax.xml.datatype.Duration;
import javax.xml.datatype.DatatypeFactory
...
Duration d = DatatypeFactory.newInstance().newDuration(time_stamp);
System.out.println(d.getHours() + "h:" + d.getMinutes() + "m: " + d.getSeconds() + "s");

For documentation see Duration and DatatypeFactory.