Test_Newsletter

// Add Shortcode
function newsletterVISTEM_shortcode( $atts ) {

	// Attributes
	extract( shortcode_atts(
		array(
			'date_start' => '',
			'date_end' => '',
			'show' => '',
		), $atts )
	);
}
add_shortcode( 'newsletterVISTEM', 'newsletterVISTEM_shortcode' );