Get the remaining time between two dates Date in Android

First you have to get the difference in milliseconds:

long diff = date1.getTime() - date2.getTime();

Then do the operations to know the difference in the unit you require:

long segundos = diff / 1000;
long minutos = segundos / 60;
long horas = minutos / 60;
long dias = horas / 24;

You must consider that when doing the integer division, a truncation error is introduced into the calculation.

With this method you can achieve it and it is similar to what you are doing:

public String getDiferencia(Date fechaInicial, Date fechaFinal){

    long diferencia = fechaFinal.getTime() - fechaInicial.getTime();

    Log.i("MainActivity", "fechaInicial : " + fechaInicial);
    Log.i("MainActivity", "fechaFinal : " + fechaFinal);

    long segsMilli = 1000;
    long minsMilli = segsMilli * 60;
    long horasMilli = minsMilli * 60;
    long diasMilli = horasMilli * 24;

    long diasTranscurridos = diferencia / diasMilli;
    diferencia = diferencia % diasMilli;

    long horasTranscurridos = diferencia / horasMilli;
    diferencia = diferencia % horasMilli;

    long minutosTranscurridos = diferencia / minsMilli;
    diferencia = diferencia % minsMilli;

    long segsTranscurridos = diferencia / segsMilli;

    return "diasTranscurridos: " + diasTranscurridos + " , horasTranscurridos: " + horasTranscurridos +
            " , minutosTranscurridos: " + minutosTranscurridos + " , segsTranscurridos: " + segsTranscurridos;


}

We determine the dates on which we want to obtain the difference:

    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/M/yyyy hh:mm:ss");
    Date fechaI = null, fechaF = null;
    try {
        fechaI = simpleDateFormat.parse("1/6/2016 12:20:12");
         //fechaF puede ser la fecha actual o tu puedes asignarala,
         //por ejemplo: fechaF = simpleDateFormat.parse("2/6/2016 15:40:42");
         fechaF = new Date(System.currentTimeMillis());
    } catch (ParseException e) {
        e.printStackTrace();
    }

From the values ​​we execute the method getDiferencia()with the initial and final date:

  Log.i(TAG,  getDiferencia(fechaI , fechaF));

The method internally prints the start and end date, so you can check the values:

fechaInicial : Wed Jun 01 00:20:12 CDT 2016
fechaFinal : Thu Jun 02 11:32:16 CDT 2016

and obtains a string with the values ​​of the difference:

diasTranscurridos: 1 , horasTranscurridos: 11 , minutosTranscurridos: 12 , segsTranscurridos: 4

I add my complete solution for my problem for future questions.

First declare the variables to use.

private TextView countDown;
private CountDownTimer countDownTimer; 
private Date eventDate, presentDate;
private Calendar calendar;
private long initialTime;

We then initialize the variable calendarwith a new instance and send the date of our future event.

 calendar = Calendar.getInstance();
 calendar.set(Calendar.YEAR, 2016);
 calendar.set(Calendar.MONTH, Calendar.AUGUST);
 calendar.set(Calendar.DAY_OF_MONTH, 20);
 calendar.set(Calendar.HOUR_OF_DAY, 7);
 calendar.set(Calendar.MINUTE, 0);
 calendar.set(Calendar.SECOND, 0);

Now we initialize the type variables Datethat are eventDate= event day and presentDate= current day, the first gets its value from the previously created calendar and the second from the current day.

 eventDate = calendar.getTime();
 presentDate = new Date();

Next step we obtain the difference in milliseconds assigning first the day of the event and then the current day, we save the results in a type variable longand send them to Logto verify that the result is not negative, if so the dates are wrongly assigned.

long diff = eventDate.getTime() - presentDate.getTime();
Log.d("dateEvent", String.valueOf(eventDate));
Log.d("dateActual", String.valueOf(presentDate));
Log.d("diff", String.valueOf(diff)); 

Next step we obtain the equivalence in days, hours, minutes and seconds with these simple mathematical operations, all the results are stored in type variables long.

This will give us the following result, for example:

diff equals 5 days 3 hours 23 minutes and 5 seconds

/**
 * Explicación:
 * segundos = (milisegundos / 1 segundo en milisegundos) mod 60 segundos de un minuto
 */
long seconds =(diff/1000)%60;
long minutes=(diff/(1000*60))%60;
long hours=(diff/(1000*60*60))%24;
long days=(diff/(1000*60*60*24))%365;

Since I need to make a counter towards the date, I initialize the variable ìnitialTimewith the value of the difference diff.

 initialTime = diff;

And then I assign the values ​​to the constructor to initialize the variable countDownTimer:

countDownTimer = new CountDownTimer(initialTime, 1000) {

            @Override
            public void onTick(long millisUntilFinished) {

                int days = (int) ((millisUntilFinished / 1000) / 86400);
                int hours = (int) (((millisUntilFinished / 1000)
                        - (days * 86400)) / 3600);
                int minutes = (int) (((millisUntilFinished / 1000)
                        - (days * 86400) - (hours * 3600)) / 60);
                int seconds = (int) ((millisUntilFinished / 1000) % 60);

                String countDownText = String.format("%2d Dias %2d Hr %2d Min %2d Seg", days, hours, minutes, seconds);
                countDown.setText(countDownText);
            }

            @Override
            public void onFinish() {
                countDown.setText(DateUtils.formatElapsedTime(0));
            }

        }.start();

With this the CountDownTimerworks from the current date to the event date.