$elements['timezone'] = [
'#type' => 'select',
'#title' => $this->t('Time zone'),
- '#options' => ['' => $this->t('- Default site/user time zone -')] + system_time_zones(FALSE),
+ '#options' => ['' => $this->t('- Default site/user time zone -')] + system_time_zones(FALSE, TRUE),
'#default_value' => $this->getSetting('timezone'),
];