if ((this.Fajardistance <= '20') && (this.Fajardistance >= '0')) {
    //if case is checking if fajar distance is equal or less than 20 mins than it will continue.

    this.CurrentTimeNotification = moment().unix();
    //checking current time using moment

    this.fajarNotification = moment(value.fajar_iqamah, 'HH:mm: A').diff(moment().startOf(this.CurrentTimeNotification), 'minutes');
    //this is calculation mins perfectly.

    //Now i am using this method for local notification
    this.localNotifications.schedule({
      text: 'Reminder for ' + value.fajar_salat + 'Iqamah',
      //at: this.fajarNotification ,
      every: this.fajarNotification,
      led: 'FF0000',
      sound: null
    });

    this.notifications.push(this.localNotifications);
  }

"at: this.fajarNotification"

"every: this.fajarNotification"