Upcoming events as month list view

function get_specified_month($uri) {
    // Look for patterns like 2099-12 at the end of the URI
    $month_pattern = '[0-9]{4}-[0-9]{2}';
    $optional_slash = '/?';
    $pattern = "#($month_pattern)($optional_slash)$#";

    // Check for matches
    $match = array();
    if (preg_match($pattern, $uri, $match) !== 1) return false;

    // We are interested only in the year/date portion
    return $match[1];
}

function upcoming_single_month_view(WP_Query $query) {
    // We are only interested in requests to view upcoming events
    if ($query->query_vars['eventDisplay'] !== 'upcoming') return;

    // Has a specific month been specified?
    $month = get_specified_month($_SERVER['REQUEST_URI']);
    if ($month === false) return;

    // Set the start date, end date
    $args = &$query->query_vars;
    $args['start_date'] = $month.'-01';
    $args['end_date'] = $month.'-31';

    return $query;
}

// We'll run our filter later than TribeEventsQuery::setArgsFromDisplayType()
add_filter('parse_tribe_event_query', 'upcoming_single_month_view', 20);