Custom Shortcode: Buy Content History

add_shortcode( 'buy_content_history', 'mycred_pro_buy_content_history' );
function mycred_pro_buy_content_history( $attr, $content = '' ) {

	if ( ! function_exists( 'mycred_render_shortcode_history' ) ) return '';

	$now = current_time( 'timestamp' );

	$start = strtotime( 'first day of last month', $now );
	$end = strtotime( 'last day of last month', $now );

	$args = array(
		'ref'  => 'buy_content',
		'time' => $start . ',' . $end
	);

	return mycred_render_shortcode_history( $args );

}