Change record status: 
Project: 
Introduced in branch: 
8.0.x
Introduced in version: 
8.0.0
Description: 

Drupal\Core\Datetime\Entity\DateFormat class variables ($id and $label) should not be accessed directly. Functions should be use to access the variable. For the variable $id use the function id(). And for the variable $label use the function label().

Impacts: 
Site builders, administrators, editors
Module developers