update: laravel 7

app/Models/Notice.php

@@ -9,4 +9,8 @@ class Notice extends Model
     protected $table = 'v2_notice';
     protected $dateFormat = 'U';
     protected $guarded = ['id'];
+    protected $casts = [
+        'created_at' => 'timestamp',
+        'updated_at' => 'timestamp'
+    ];
 }