Asp.net model date testing

Say I have a model for a product:

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime Created { get; set; }
    ...
}

For this product I have a Dto:

public class ProductDto
{
    [Required]
    public string Name { get; set; }
    ...
}

Now, In my controller, I have a method that "creates" new products and records the current time in the Created attribute:

public IHttpActionResult PostProduct(ProductDto dto)
{
    return Ok(new Product()
    {
        Created = DateTime.Now,
        Name = dto.Name
    });
}

Say I wanted to unit test this method to verify that a newly created product is assigned a DateTime object other than the default {01-01-0001 00:00:00} it gets from the prop snippet, how would I go about that? I would prefer that Created, in the model, is not nullable.