wp_timezone_choice( string $selected_zone, string $locale = null ): string

6759function wp_timezone_choice( $selected_zone, $locale = null ) {6760	static $mo_loaded = false, $locale_loaded = null;6761 6762	$continents = array( 'Africa', 'America', 'Antarctica', 'Arctic', 'Asia', 'Atlantic', 'Australia', 'Europe', 'Indian', 'Pacific' );6763 6764	// Load translations for continents and cities.6765	if ( ! $mo_loaded || $locale !== $locale_loaded ) {6766		$locale_loaded = $locale ? $locale : get_locale();6767		$mofile        = WP_LANG_DIR . '/continents-cities-' . $locale_loaded . '.mo';6768		unload_textdomain( 'continents-cities', true );6769		load_textdomain( 'continents-cities', $mofile, $locale_loaded );6770		$mo_loaded = true;6771	}6772 6773	$tz_identifiers = timezone_identifiers_list();6774	$zonen          = array();6775 6776	foreach ( $tz_identifiers as $zone ) {6777		$zone = explode( '/', $zone );6778		if ( ! in_array( $zone[0], $continents, true ) ) {6779			continue;6780		}6781 6782		// This determines what gets set and translated - we don't translate Etc/* strings here, they are done later.6783		$exists    = array(6784			0 => ( isset( $zone[0] ) && $zone[0] ),6785			1 => ( isset( $zone[1] ) && $zone[1] ),6786			2 => ( isset( $zone[2] ) && $zone[2] ),6787		);6788		$exists[3] = ( $exists[0] && 'Etc' !== $zone[0] );6789		$exists[4] = ( $exists[1] && $exists[3] );6790		$exists[5] = ( $exists[2] && $exists[3] );6791 6792		// phpcs:disable WordPress.WP.I18n.LowLevelTranslationFunction,WordPress.WP.I18n.NonSingularStringLiteralText6793		$zonen[] = array(6794			'continent'   => ( $exists[0] ? $zone[0] : '' ),6795			'city'        => ( $exists[1] ? $zone[1] : '' ),6796			'subcity'     => ( $exists[2] ? $zone[2] : '' ),6797			't_continent' => ( $exists[3] ? translate( str_replace( '_', ' ', $zone[0] ), 'continents-cities' ) : '' ),6798			't_city'      => ( $exists[4] ? translate( str_replace( '_', ' ', $zone[1] ), 'continents-cities' ) : '' ),6799			't_subcity'   => ( $exists[5] ? translate( str_replace( '_', ' ', $zone[2] ), 'continents-cities' ) : '' ),6800		);6801		// phpcs:enable6802	}6803	usort( $zonen, '_wp_timezone_choice_usort_callback' );6804 6805	$structure = array();6806 6807	if ( empty( $selected_zone ) ) {6808		$structure[] = '<option selected="selected" value="">' . __( 'Select a city' ) . '</option>';6809	}6810 6811	// If this is a deprecated, but valid, timezone string, display it at the top of the list as-is.6812	if ( in_array( $selected_zone, $tz_identifiers, true ) === false6813		&& in_array( $selected_zone, timezone_identifiers_list( DateTimeZone::ALL_WITH_BC ), true )6814	) {6815		$structure[] = '<option selected="selected" value="' . esc_attr( $selected_zone ) . '" dir="auto">' . esc_html( $selected_zone ) . '</option>';6816	}6817 6818	foreach ( $zonen as $key => $zone ) {6819		// Build value in an array to join later.6820		$value = array( $zone['continent'] );6821 6822		if ( empty( $zone['city'] ) ) {6823			// It's at the continent level (generally won't happen).6824			$display = $zone['t_continent'];6825		} else {6826			// It's inside a continent group.6827 6828			// Continent optgroup.6829			if ( ! isset( $zonen[ $key - 1 ] ) || $zonen[ $key - 1 ]['continent'] !== $zone['continent'] ) {6830				$label       = $zone['t_continent'];6831				$structure[] = '<optgroup label="' . esc_attr( $label ) . '" dir="auto">';6832			}6833 6834			// Add the city to the value.6835			$value[] = $zone['city'];6836 6837			$display = $zone['t_city'];6838			if ( ! empty( $zone['subcity'] ) ) {