gistfile1.php

if( ! function_exists( 'wp_date_format_php_to_js') ){
	/**
	 * Convert a date format to a jQuery UI DatePicker format
	 *
	 * @param string $dateFormat a date format
	 *
	 * @return string
	 */
	function wp_date_format_php_to_js( $dateFormat ) {
		$chars = array(
			// Day
			'd' => 'dd',
			'j' => 'd',
			'l' => 'DD',
			'D' => 'D',
			// Month
			'm' => 'mm',
			'n' => 'm',
			'F' => 'MM',
			'M' => 'M',
			// Year
			'Y' => 'yy',
			'y' => 'y',
		);
		return strtr( (string) $dateFormat, $chars );
	}
}