https://api.drupal.org/api/drupal/core%21modules%21datetime%21src%21Plugin%21Field%21FieldFormatter%21DateTimeFormatterBase.php/function/DateTimeFormatterBase%3A%3AsettingsSummary/8.9.x
function DateTimeFormatterBase::settingsSummary | Drupal API
functiondrupalapi
https://api.drupal.org/api/drupal/core%21modules%21datetime%21src%21Plugin%21Field%21FieldFormatter%21DateTimeFormatterBase.php/function/DateTimeFormatterBase%3A%3AsetTimeZone/9
function DateTimeFormatterBase::setTimeZone | Drupal API
functiondrupalapi