数据库时间字段cast

app/Models/Programs.php

@@ -7,7 +7,6 @@ use Illuminate\Database\Eloquent\Model;
 class Programs extends Model
 {
     protected $fillable = ["name", "difficulty", "desc"];
-    protected $dateFormat = 'U';
     public function appends(): \Illuminate\Database\Eloquent\Relations\HasMany
     {
         return $this->hasMany(ProgramAppends::class, "program_id", "id")->orderByDesc("is_original")->orderBy("created_at");