WordPress shortcode - Hide content on Monday

<?php

/*
Plugin Name: Hide On Monday
Plugin URI: http://www.damiencarbery.com
Description: Hide the content on Monday.
Author: Damien Carbery
Version: 0.1

*/

add_shortcode('hide-on-monday', 'sc_hom');

function sc_hom($atts, $content, $code) {
    define('tm_wday', 6);  // Defines for code readability
    define('monday', 1);
    $localtime = localtime();
    if(monday == $localtime[tm_wday]) {  // or: if(1 == $localtime[6])
        return '';
    }

    return $content;
}