DrupalDateTime class not work

Question

I try to use the DrupalDateTime class in my theme to show native date and time in custom format based on special TimeZone in my nodes.

According to New Datetime API DrupalDateTime should be used instead of the PHP DateTime class or to functions like date(), gmdate(), or strtotime().

I am using the following code in a theme.

function MyThemeName_preprocess_node(&$variables){
  $node_date = $variables['node']->getCreatedTime();
  $date = new DrupalDateTime($node_date, 'UTC');
  $date->setTimezone(new \DateTimeZone('Asia/Tehran'));
  $variables['date'] = $date->format('Y/m/d');
}

I get this error

Exception: DateTime object not set. in Drupal\Component\Datetime\DateTimePlus->__call() (line 308 of core\lib\Drupal\Component\Datetime\DateTimePlus.php).

Answer 1

The code you are showing is wrong because DrupalDateTime::__construct() is expecting a string, while you are passing an integer, which is what Node::getCreatedTime() returns.

Instead of DrupalDateTime::__construct(), you should use DrupalDateTime::createFromTimestamp().

$date = DrupalDateTime::createFromTimestamp($variables['node']->getCreatedTime(), 'UTC');

Since the static method also accept a \DateTimeZone object as second parameter, your code could be similar to the following one.

if (isset($variables['node'])) {
  $date = DrupalDateTime::createFromTimestamp($variables['node']->getCreatedTime(), new \DateTimeZone('Asia/Tehran'));
  $variables['date'] = $date->format('Y/m/d');
}

Since you seem interested to get strings in a specific language, you should also set the language code.

if (isset($variables['node'])) {
  $date = DrupalDateTime::createFromTimestamp($variables['node']->getCreatedTime(), new \DateTimeZone('Asia/Tehran'), ['langcode' => 'the language code for the language you need']);
  $variables['date'] = $date->format('Y/m/d');
}

Answer 2

if you want to retrun date in Shamsi(jalalian) try to convert it with

 if (isset($variables['node'])) {
 $timestamp = strtotime($variables['node']->getCreatedTime()); 
 $format = 'Y/m/d';
 $timezone = date_default_timezone_get();
 $date = new \IntlDateFormatter("fa_IR@calendar=persian", \IntlDateFormatter::FULL, \IntlDateFormatter::SHORT, $timezone, \IntlDateFormatter::TRADITIONAL);
 $date->setPattern($format);
 $variables['jdate']  =  $date->format(intval($timestamp));
}