In Drupal 8, the process of adding a new date format is substantially simpler than in Drupal 7.
In Drupal 7, there were several steps involved.
In Drupal 8, the process is substantially simpler:
- Go to Configuration > Date and time formats.
- You'll see that Drupal 8 ships with around a dozen formats, compared with 3 in Drupal 7.
- Click the blue "Add format" button:
You can now add a date format directly into the "Format string" field.
You wil need to use the PHP syntax on this page. Drupal will give you a live preview of your date format: