ziziove000000

Thanks for your help,
Code is changed like:

<?php

add_filter('updraftplus_backup_intervals', 'local_updraftplus_backup_intervals', 10, 2);
function local_updraftplus_backup_intervals($ints, $what_for) {
    // $what_for is either 'db' or 'files'
    if ('db' == $what_for) $ints['twodays'] = 'twodays';
    return $ints;
}

add_filter('cron_schedules', 'local_cron_schedules', 31);
function local_cron_schedules($schedules) {
    $schedules['twodays'] = array('interval' => 172800, 'display' => 'twodays');
    return $schedules;
}

Is it run for both database and all files? or just database?

thanks in advance!

@simon110324 Thank you so much for your solution.
It works!