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();