Java – Calculate difference between two times android

I am developing and android app, where I need to calculate the difference between two times.I need to calculate the time difference for 24 hrs, and also the difference between times on two days(Eg. 5pm today to 9 am tomorrow).

I have tried the below code, to calculate the difference which works only for 24 hrs,

String dateStart = "08:00:00";
String dateStop = "13:00:00";

//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");

Date d1 = null;
Date d2 = null;

try 
{
    d1 = format.parse(dateStart);
    d2 = format.parse(dateStop);

    //in milliseconds
    long diff = d2.getTime() - d1.getTime();
    long diffHours = diff / (60 * 60 * 1000) % 24;
    Log.e("test",diffHours + " hours, ");
}
catch (Exception e) 
{
    // TODO: handle exception
}