Не правильно по времени срабатывает alarmManager. Подскажите в чем ошибка, пожалуйста

import android.app.AlarmManager;
import android.app.IntentService;
import android.app.Notification;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.icu.util.Calendar;
import android.os.Build;
import android.support.annotation.Nullable;
import android.support.annotation.RequiresApi;
import android.support.v4.app.NotificationManagerCompat;
import android.util.Log;
import com.example.yass.remindme.MainActivity;
import com.example.yass.remindme.R;
import com.example.yass.remindme.db.SharedPreferencesHelper;
import com.example.yass.remindme.models.TimeRefresh;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
 * Created by yass on 4/14/17.
 */
public class IntentServiceNotification extends IntentService {
    private static final String TAG = "IntentService";
    private static long POLL_INTERVAL = 0;
    public IntentServiceNotification() {
        super(TAG);
    }

    @Override
    protected void onHandleIntent(@Nullable Intent intent) {
        //  if (SharedPreferencesHelper.getInstance().getStatusTimeRefresh() == 1) {
        sendNotification();
        // }
    }

    public static void setServiceAlarm(Context context, boolean isOn) {
        Intent intent = new Intent(context, IntentServiceNotification.class);
        PendingIntent pendingIntent = PendingIntent.getService(context, 15, intent, 0);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(context.ALARM_SERVICE);
        POLL_INTERVAL = getPollInterval();
        TimeRefresh timeRefresh = SharedPreferencesHelper.getInstance().getTimeRefresh();
        java.util.Calendar calendar = java.util.Calendar.getInstance();
        calendar.set(java.util.Calendar.HOUR_OF_DAY, timeRefresh.getHourDate());
        calendar.set(java.util.Calendar.MINUTE, timeRefresh.getMinutesDate());
        if (isOn) {
            alarmManager.setRepeating(AlarmManager.RTC, System.currentTimeMillis(), calendar.getTimeInMillis(), pendingIntent);
        } else {
            alarmManager.cancel(pendingIntent);
            pendingIntent.cancel();
        }
    }
    public static long getPollInterval() {
        TimeRefresh timeRefresh = SharedPreferencesHelper.getInstance().getTimeRefresh();
        int[] days = timeRefresh.getDayOfWeek();
        int currentTimeMillis = (timeRefresh.getHourDate() * 3600000 )+ (timeRefresh.getMinutesDate() * 60000);
        Log.i(TAG, "Current Millisec = " + currentTimeMillis  + " Days = " + days[0] + " "
                + days[1] + " " + days[2] + " " + days[3] + " " + days[4] + " " + days[5] + " " + days[6]);

        if ((timeRefresh.getHourDate() + timeRefresh.getMinutesDate()) > 43200000){
            return   (currentTimeMillis - (timeRefresh.getHourDate() + timeRefresh.getMinutesDate()));
        } else {
            return  ((currentTimeMillis - 86400000) + currentTimeMillis + timeRefresh.getHourDate() + timeRefresh.getMinutesDate());
        }
    }
    private void sendNotification() {
        Notification.Builder builder = new Notification.Builder(this);
        Intent intent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
                0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
        builder.setContentIntent(pendingIntent)
                .setSmallIcon(R.drawable.alarm_clock)
                .setContentTitle("Remind !!!")
                .setContentText("Time to go");
        Notification notification = builder.build();
        NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(this);
        notificationManagerCompat.notify(16, notification);
    }
}