问时间表提醒在确切的时间

EN

register_activation_hook(__FILE__, 'cron_activation_function'); //to add cron to the cron table when plugin gets activated.
add_action('the_name_tag_of_your_cron_in_cron_table', 'the_cron_function_to_run');
register_deactivation_hook(__FILE__, 'cron_deactivation_function'); //to remove cron from the cron table when plugin gets deactivated.

function cron_activation_function()
{
    if (!wp_next_scheduled('the_name_tag_of_your_cron_in_cron_table')) {
        wp_schedule_event(time(), 'hourly', 'the_name_tag_of_your_cron_in_cron_table');
    }
}

function cron_deactivation_function()
{
    wp_clear_scheduled_hook('the_name_tag_of_your_cron_in_cron_table');
}

function the_cron_function_to_run() 
{
    //do what ever you want then send the emails
}