How to create everyday notifications at certain time in Android?

This example demonstrate about How to create everyday notifications at certain time in Android
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<? xml version = "1.0" encoding = "utf-8" ?>
<RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android"
   xmlns: tools = "http://schemas.android.com/tools"
   android :layout_width = "match_parent"
   android :layout_height = "match_parent"
   android :padding = "16dp"
   tools :context = ".MainActivity" >
   <TextView
      android :id = "@+id/tvDate"
      android :layout_width = "match_parent"
      android :layout_height = "wrap_content"
      android :hint = "Select Date"
      android :onClick = "setDate"
      android :padding = "16dp" />
</RelativeLayout>
Step 3 − Add the following code to src/MainActivity.
package app.tutorialspoint.com.notifyme ;
import android.app.AlarmManager ;
import android.app.DatePickerDialog ;
import android.app.Notification ;
import android.app.PendingIntent ;
import android.content.Context ;
import android.content.Intent ;
import android.os.Bundle ;
import android.support.v4.app.NotificationCompat ;
import android.support.v7.app.AppCompatActivity ;
import android.view.View ;
import android.widget.Button ;
import android.widget.DatePicker ;
import java.text.SimpleDateFormat ;
import java.util.Calendar ;
import java.util.Date ;
import java.util.Locale ;
public class MainActivity extends AppCompatActivity {
   public static final String NOTIFICATION_CHANNEL_ID = "10001" ;
   private final static String default_notification_channel_id = "default" ;
   Button btnDate ;
   final Calendar myCalendar = Calendar. getInstance () ;
   @Override
   protected void onCreate (Bundle savedInstanceState) {
      super .onCreate(savedInstanceState) ;
      setContentView(R.layout. activity_main ) ;
      btnDate = findViewById(R.id. btnDate ) ;
   }
   private void scheduleNotification (Notification notification , long delay) {
      Intent notificationIntent = new Intent( this, MyNotificationPublisher. class ) ;
      notificationIntent.putExtra(MyNotificationPublisher. NOTIFICATION_ID , 1 ) ;
      notificationIntent.putExtra(MyNotificationPublisher. NOTIFICATION , notification) ;
      PendingIntent pendingIntent = PendingIntent. getBroadcast ( this, 0 , notificationIntent , PendingIntent. FLAG_UPDATE_CURRENT ) ;
      AlarmManager alarmManager = (AlarmManager) getSystemService(Context. ALARM_SERVICE ) ;
      assert alarmManager != null;
      alarmManager.set(AlarmManager. ELAPSED_REALTIME_WAKEUP , delay , pendingIntent) ;
   }
   private Notification getNotification (String content) {
      NotificationCompat.Builder builder = new NotificationCompat.Builder( this, default_notification_channel_id ) ;
      builder.setContentTitle( "Scheduled Notification" ) ;
      builder.setContentText(content) ;
      builder.setSmallIcon(R.drawable. ic_launcher_foreground ) ;
      builder.setAutoCancel( true ) ;
      builder.setChannelId( NOTIFICATION_CHANNEL_ID ) ;
      return builder.build() ;
   }
   DatePickerDialog.OnDateSetListener date = new DatePickerDialog.OnDateSetListener() {
      @Override
      public void onDateSet (DatePicker view , int year , int monthOfYear , int dayOfMonth) {
         myCalendar .set(Calendar. YEAR , year) ;
         myCalendar .set(Calendar. MONTH , monthOfYear) ;
         myCalendar .set(Calendar. DAY_OF_MONTH , dayOfMonth) ;
         updateLabel() ;
      }
   } ;
   public void setDate (View view) {
      new DatePickerDialog(MainActivity. this, date ,
         myCalendar .get(Calendar. YEAR ) ,
         myCalendar .get(Calendar. MONTH ) ,
         myCalendar .get(Calendar. DAY_OF_MONTH )
      ).show() ;
   }
   private void updateLabel () {
      String myFormat = "dd/MM/yy" ; //In which you need put here
      SimpleDateFormat sdf = new SimpleDateFormat(myFormat , Locale. getDefault ()) ;
      Date date = myCalendar .getTime() ;
      btnDate .setText(sdf.format(date)) ;
      scheduleNotification(getNotification( btnDate .getText().toString()) , date.getTime()) ;
   }
}
Step 4 − Add the following code to src/MyNotificationPublisher.
package app.tutorialspoint.com.notifyme ;
import android.app.Notification ;
import android.app.NotificationChannel ;
import android.app.NotificationManager ;
import android.content.BroadcastReceiver ;
import android.content.Context ;
import android.content.Intent ;
import static app.tutorialspoint.com.notifyme.MainActivity. NOTIFICATION_CHANNEL_ID ;
public class MyNotificationPublisher extends BroadcastReceiver {
   public static String NOTIFICATION_ID = "notification-id" ;
   public static String NOTIFICATION = "notification" ;
   public void onReceive (Context context , Intent intent) {
      NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context. NOTIFICATION_SERVICE ) ;
      Notification notification = intent.getParcelableExtra( NOTIFICATION ) ;
      if (android.os.Build.VERSION. SDK_INT >= android.os.Build.VERSION_CODES. O ) {
         int importance = NotificationManager. IMPORTANCE_HIGH ;
         NotificationChannel notificationChannel = new NotificationChannel( NOTIFICATION_CHANNEL_ID , "NOTIFICATION_CHANNEL_NAME" , importance) ;
         assert notificationManager != null;
         notificationManager.createNotificationChannel(notificationChannel) ;
      }
      int id = intent.getIntExtra( NOTIFICATION_ID , 0 ) ;
      assert notificationManager != null;
      notificationManager.notify(id , notification) ;
   }
}
Step 5 − Add the following code to AndroidManifest.xml
<? xml version = "1.0" encoding = "utf-8" ?>
<manifest xmlns: android = "http://schemas.android.com/apk/res/android"
   package = "app.tutorialspoint.com.notifyme" >
   <uses-permission android :name = "android.permission.VIBRATE" />
   <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= ".MyNotificationPublisher" />
   </application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −
Click  here  to download the project code