模型数据如何呈现为laravel

I have a model that I want to return as json. I want to return the timestamps as well. The problem is that the timestamps is saved in the following format 2013-10-02 09:45:22 but i want it in a different format. I still want the original format in the database but when it is outputted as JSON i want 2013.10.02. I found that you can override getDateFormat() but it does seem to change the format used in the db to.

I can always loop through the data before it is returned but it seems like this kind of code belongs in the model.

Updated with answer:

This Add a custom attribute to a Laravel / Eloquent model on load? explains how this works.

class User extends Eloquent {

    protected $appends = array('my_date');    

    public function getMyDateAttribute()
    {
        return date('Y.m.d',strtotime($this->attributes['created_at']));
    }

}

The critical part is the protected variable $appends which ensures that the accessor is included when the object is converted either with toArray or to Json.

You can create an additional accessor like:

class User extends Eloquent {

    protected $appends = array('my_date');

    public function setMyDateAttribute($value)
    {
         return $this->attributes['my_date'] = $value;
    }

    public function getMyDateAttribute($value)
    {
        return date('Y-m-d', strtotime($this->attributes['created_at']) );
    }

}

and then use it like User->my_date;