1364 Field 'schedule_id' doesn't have a default value

Schedule_id field not found

//controller code

public function store(Request $request) {

    $schedule = new menu;
    $days = new day;
    $schedule->scheduleName = $request->name;
    $schedule->sensor = $request->sensor;
    $schedule->start_time = $request->start_time;
    $schedule->end_time = $request->end_time;
    $schedule->timestamps = false;
    $schedule->s_daytime = $request->s_daytime;
    $schedule->e_daytime = $request->e_daytime;
    $days->days = $request->days;
    $days->timestamps = false;
    $days->save();
    $schedule->save();




    return view('store');

}

class menu extends Model { protected $table = "schedule";

protected $fillable = [
    'scheduleName', 'start_time', 'end_time','sensor','s_daytime','e_daytime',

];
public function days()
{
    return $this->hasMany('App\day');
}

}

via Chebli Mohamed