Create a node With date field

It is same as normal node creation but must be in format "Y-m-d" (YYYY-MM-DD)

Example:

$dateTime = \DateTime::createFromFormat('Y-m-d','2000-01-30');
$newDateString = $dateTime->format('Y-m-d\TH:i:s');
$node = \Drupal\node\Entity\Node::create(array(
          'type' => 'article',
          'title' => 'The title',
          'langcode' => 'en',
          'uid' => 1,
          'status' => 1,
          'body' => array('The body text'),
          //'field_date' => array("2000-01-30"),
          'field_date' => $newDateString,
    ));
$node->save();