Créer une tâche crontab qui s’exécute chaque jour

/**
 *  PIT - Cron schedule + Event
 *  - Add custom daily schedule + schedule event
 */
add_action('init', '_pit_schedule_event_custom');
function _pit_schedule_event_custom() {

    /**
     *  1. Add custom daily schedule
     */
    add_filter('cron_schedules', '_pit_daily_cron_schedule_custom');
    function _pit_daily_cron_schedule_custom($schedules) {
        $schedules['_pit_daily'] = array(
            'interval' => DAY_IN_SECONDS,
            'display' => __('Every day', 'pilot-theme')
        );
        return $schedules;
    }

    /**
     *  2. Add event "_pit_event_custom" at 6AM the next day
     */
    $event_args     = array();
    $event_name     = '_pit_event_custom';
    $event_schedule = '_pit_daily';
    $event_time     = strtotime(date('d F Y 06h00') . '+1 day', time());

    /**
     *  If the event is not already scheduled, schedule it. 
     */
    if (!wp_next_scheduled($event_name, $event_args))
        wp_schedule_event($event_time, $event_schedule, $event_name, $event_args);
}

/**
 *  PIT - Event
 *  - Your custom event code
 */
add_action('_pit_event_custom', '_pit_action_daily_custom', 10, 1);
function _pit_action_daily_custom() {

    // Your code that do something here daily

}