Будильник на Android

Разрабатываю будильник для ознакомления со сферой разработки для Android.
Проблема в следующем: не работает будильник.
Не могу разобраться в чём проблема. Прошу помощи.

Код:

package com.example.llirik.alarmtest;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TimePicker;
import android.widget.Toast;
import java.util.Calendar;
public class MainActivity extends AppCompatActivity {
    private Button btnSave;
    private TimePicker tpClock;
    private PendingIntent pendingIntent;
    AlarmManager alarmManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnSave = (Button) findViewById(R.id.btnSave);
        tpClock = (TimePicker) findViewById(R.id.tpClock);
        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        final Calendar calendar = Calendar.getInstance();
        final Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
        btnSave.setOnClickListener(new View.OnClickListener() {
            @RequiresApi(api = Build.VERSION_CODES.M)
            @Override
            public void onClick(View v) {
                calendar.set(Calendar.HOUR, tpClock.getHour());
                calendar.set(Calendar.MINUTE, tpClock.getMinute());
                AlarmReceiver alarmReceiver = new AlarmReceiver();
                alarmReceiver.SetAlarm(getApplicationContext(), calendar.getTimeInMillis());
                Toast.makeText(getApplicationContext(), "Alarm set", Toast.LENGTH_LONG).show();
            }
        });
    }
}

AlarmReciver ->

package com.example.llirik.alarmtest;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.PowerManager;
import android.util.Log;
import android.widget.Toast;
public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent){
        PowerManager pm=(PowerManager) context.getSystemService(Context.POWER_SERVICE);
        PowerManager.WakeLock wl= pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"Alarm worked");
        wl.acquire();
        Toast.makeText(context, "Alarm work", Toast.LENGTH_LONG).show();
        wl.release();
    }
    public void SetAlarm(Context context, long timeInMillisecond)
    {
        AlarmManager am=(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
        Intent intent=new Intent(context, AlarmReceiver.class);
        PendingIntent pi= PendingIntent.getBroadcast(context,0, intent,0);
        am.set(AlarmManager.RTC_WAKEUP, timeInMillisecond,pi);
        Log.d("TAG_LOG", "Alarm set");
    }
}

Файл манифеста ->

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.llirik.alarmtest">
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver android:name=".AlarmReceiver"/>
    </application>
    <uses-permission android:name="android.permission.WAKE_LOCK"/>
</manifest>