Cannot delete date field items when number of values is configured as "unlimited"

Cannot delete date field items when number of values is configured as "unlimited"

To reproduce:
- Create a new drupal installation with the minimal install profile
- Install field_ui and date modules
- Add a content type "test" with a date field.
- Set, in the date field, the number of values as unlimited
- Create a new "test" node
- In the date field, click on "add another item" button, and it will work, but you cannot delete items

Doesn't matter wich widget you choose, tested with textfield and calendar popup widgets