No Field-Format in Drupal 11.1.4

Hey... I played bit more around so it seems to work with plane datefield but not when i wanna use a timespan filed with start / end time and date and time.

hey i changed now:

in FlipDownFormatter.php

/**
 * @FieldFormatter(
 *   id = "flipdown",
 *   label = @Translation("FlipDown countdown"),
 *   field_types = {
 *     "datetime",
 *     "timestamp",
 *     "daterange"
 *   }
 * )
 */

and added "Datarange" and also added "Datarange" in flipdown.views.inc .. now i pick the format in my View it also will show kind of correct .. so JS script is loaded the counter counts etc but the time is off by 2 Hours .. my Server, PHP, Durpal all is set to "Berlin" as timezone but the Module gives back:

UTC Timestamp: 1753822800 (2025-07-29T23:00:00+02:00)

Instead of "2025-07-30T01:00:00+02:00". Unfortunately i dont have real clue about Drupal DEV or PHP .. i just messaround with AI and good luck. Maybe some else can give a hint what is going with the Timezone here?!

Hey,

first thank you for looking in to it, i really appreciate it :)

I messed bit more around with AI and found a Soultion?!... its just code from ChatGPT but it seems to work now.

Change:
File: FlipDownFormatter.php

Original Code:

      // Convert stored value to Unix seconds.
      if (is_numeric($item->value)) {
        $target_ts = (int) $item->value;
      }
      else {
        try {
         $target_ts = (new DrupalDateTime($item->value))->getTimestamp();
        } catch (\Exception $e) {
          continue;
        }
     } 

Replacement:

      try {
  $timezone = new \DateTimeZone(\Drupal::config('system.date')->get('timezone.default'));

  if (is_numeric($item->value)) {
    // Timestamp in seconds → treat as UTC
    $date = new \DateTime('@' . $item->value);
  } else {
    // ISO string or date as string → first interpret in UTC
    $date = new \DateTime($item->value, new \DateTimeZone('UTC'));
  }

  $date->setTimezone($timezone);
  $target_ts = $date->getTimestamp();

} catch (\Exception $e) {
  continue;
}