bot-28/app/Models/ActivityReward.php

<?php

namespace App\Models;

use Carbon\Carbon;

class ActivityReward extends BaseModel
{
    protected $table = 'activity_rewards';
    protected $fillable = [
        'title', 'sub_title', 'detail_image'
        , 'start_time', 'end_time'
    ];

    protected function getStartTimeAttribute($value): string
    {
        return date('Y-m-d', $value);
    }

    protected function getEndTimeAttribute($value): string
    {
        return date('Y-m-d', $value);
    }

}