Can't create fixtures with dates - php

Question

I have the following User entity and fixture file, but when I run app/console doctrine:fixtures:load I get the following error and not sure why. If I remove the date fields the fixtures generate fine. What am I missing here? Thanks.
The error: Could not determine how to assign created_at to a AppBundle\Entity\User object
<?php
namespace AppBundle\Entity;
use Gedmo\Mapping\Annotation as Gedmo;
use Doctrine\ORM\Mapping as ORM;
/**
* User
*
* #ORM\Table()
* #ORM\Entity(repositoryClass="AppBundle\Entity\UserRepository")
*/
class User
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=255)
*/
private $name;
/**
* #var string
*
* #ORM\Column(name="role", type="string", length=255)
*/
private $role;
/**
* #var string
*
* #ORM\Column(name="email", type="string", length=255)
*/
private $email;
/**
* #var string
*
* #ORM\Column(name="phone", type="string", length=16)
*/
private $phone;
/**
* #var \DateTime
*
* #Gedmo\Timestampable(on="create")
* #ORM\Column(name="created_at", type="datetime", nullable=true)
*/
private $createdAt;
/**
* #var \DateTime
*
* #Gedmo\Timestampable(on="update")
* #ORM\Column(name="updated_at", type="datetime", nullable=true)
*/
private $updatedAt;
And my fixture yml:
AppBundle\Entity\User:
user{1..10}:
name: <firstName()> <lastName()>
role: employee
email: <email()>
phone: <numberBetween(1555000000, 1555999999)>
created_at: <datetimeBetween('-5 days', 'now')>
updated_at: <datetimeBetween('-5 days', 'now')>

Answer 1

Not sure, but I believe that the naming is not correct, just what the error is saying. I think it should be:
createdAt: <datetimeBetween('-5 days', 'now')>
updatedAt: <datetimeBetween('-5 days', 'now')>

Answer 2

I am afraid you can't set timestampable fields manually. In documentation and entity example there are no setters at all for such fields. So in fixtures you can simply remove created_at and updated_at (they will be set automatically):
ppBundle\Entity\User:
user{1..10}:
name: <firstName()> <lastName()>
role: employee
email: <email()>
phone: <numberBetween(1555000000, 1555999999)>