<?php
defined('ABSPATH') or exit;

$options = (array) get_option('mc4wp', array());
if (empty($options['allow_usage_tracking'])) {
    return;
}

// usage tracking is enabled, reschedule it so it uses new cron schedule.

// make sure 'monthly' cron schedule is registered
/**
 * @ignore
 */
function _mc4wp_303_add_monthly_cron_schedule($schedules)
{
    $schedules['monthly'] = array(
        'interval' => 30 * DAY_IN_SECONDS,
        'display' => 'Once a month'
    );

    return $schedules;
}

add_filter('cron_schedules', '_mc4wp_303_add_monthly_cron_schedule', 1);

// reschedule usage tracking event
wp_clear_scheduled_hook('mc4wp_usage_tracking');
wp_schedule_event(time(), 'monthly', 'mc4wp_usage_tracking');