Change Upcoming slug to List (The Events Calendar)

/**
 * Change the "upcoming" string (from The Events Calendar) to "list".
 *
 * Alternatively (and probably more efficiently) this change could be made in
 * a .mo/.po translation file.
 *
 * @param string $translated
 * @param string $untranslated
 * @param string $domain
 * @return string
 */
function changeUpcomingEventsSlug($translated, $untranslated, $domain) {
    if ($untranslated === 'upcoming' and $domain === 'tribe-events-calendar') {
        remove_filter('gettext', __FUNCTION__, 20, 3);
        return 'list';
    }
    else return $translated;
}


/**
 * Set up a filter to change "upcoming" to "list".
 *
 * Before this works effectively you will need to flush the rewrite rules.
 * Normally, visiting Settings > Permalinks (no need to change anything) is
 * sufficient to do this.
 */
add_filter('gettext', 'changeUpcomingEventsSlug', 20, 3);