timezone error when casting a naive date in a Daylight Saving Time Change

[Clara]

When you use a model with datetime with a timezone active and naive data as input, it raise the follow error:

File "<basepath>/lib/python3.7/site-packages/pytz/tzinfo.py", line 234, in localize
    raise AmbiguousTimeError(dt)
pytz.exceptions.AmbiguousTimeError: 2020-10-25 02:00:01

The steps to reproduce are:

1. Use a model with datetime: In this example, we are going to create a user model that extends AbstractUser, but you could use any model with a datetime field

class User(AbstractUser):
    class Meta:
        db_table = 'my_user'

    created_at = models.DateTimeField(default=timezone.now)
    updated_at = models.DateTimeField(auto_now=True)
    last_password_change = models.DateTimeField(null=True)

2. Create an object with a string naive date:

    User.objects.create(
        email = "test@amail.it",
        username = "user_25",
        created_at = "2020-10-25 02:00:01"
    )

• The timezone settings are:

TIME_ZONE = 'Europe/Rome'
USE_TZ = True

Database configuration has not timezone set