How to print date in format «long» on node.html.twig template? Try this code (at node.html.twig, Drupal 8.0.0-rc3):

{% set date = node.created|format_date('long') %}


And next:

{{ dump(date) }}


Return error:

Exception: The timestamp must be numeric. in Drupal\Component\Datetime\DateTimePlus::createFromTimestamp() (line 165 of core/lib/Drupal/Component/Datetime/DateTimePlus.php).

Drupal\Core\Datetime\DateFormatter-&gt;format(Object, 'long')
you are not using the actual timestamp. Here's what you should do:

{% set date = node.createdtime|format_date('long') %}


See? You only need to replace created with createdtime.
Hope this helps.