function wp_localize_jquery_ui_datepicker() {
	global $wp_locale;

	if ( ! wp_script_is( 'jquery-ui-datepicker', 'enqueued' ) ) {
		return;
	}

	// Convert the PHP date format into jQuery UI's format.
	$datepicker_date_format = str_replace(
		array(
			'd',
			'j',
			'l',
			'z', // Day.
			'F',
			'M',
			'n',
			'm', // Month.
			'Y',
			'y',            // Year.
		),
		array(
			'dd',
			'd',
			'DD',
			'o',
			'MM',
			'M',
			'm',
			'mm',
			'yy',
			'y',
		),
		get_option( 'date_format' )
	);

	$datepicker_defaults = wp_json_encode(
		array(
			'closeText'       => __( 'Close' ),
			'currentText'     => __( 'Today' ),
			'monthNames'      => array_values( $wp_locale->month ),
			'monthNamesShort' => array_values( $wp_locale->month_abbrev ),
			'nextText'        => __( 'Next' ),
			'prevText'        => __( 'Previous' ),
			'dayNames'        => array_values( $wp_locale->weekday ),
			'dayNamesShort'   => array_values( $wp_locale->weekday_abbrev ),
			'dayNamesMin'     => array_values( $wp_locale->weekday_initial ),
			'dateFormat'      => $datepicker_date_format,
			'firstDay'        => absint( get_option( 'start_of_week' ) ),
			'isRTL'           => $wp_locale->is_rtl(),
		)
	);

	wp_add_inline_script( 'jquery-ui-datepicker', "jQuery(document).ready(function(jQuery){jQuery.datepicker.setDefaults({$datepicker_defaults});});" );
}