It seems with every new WordPress version there is the same issue. For one reason or another, post scheduling stops working. Exact cause is varied but most commonly it is the caching plugin playing games.
Usual solutions for this are either manually calling wp-cron.php via wget or getting WP Scheduled Plugin. I believe most sites, including mine, need another plugin as much as pig needs a wig. I am not judging if you are into either of it, but I recommend limiting both activities.
Using curl or wget to manually execute wp-cron.php might also not work on sites that are properly secured and have most of php disabled in .htaccess to start with. Yes, you can always make an exception, but there is a better way.
First step is common, just disable standard WordPress cron behavior in wp-config.php:
define('DISABLE_WP_CRON', true);Then either use crontab -e from command line or your web provider's task scheduling web interface (CPanel or similar) to add following command:
/usr/bin/php -q /home/user/www/wp-cron.phpThis will call upon PHP to manually execute wp-cron.php bypassing Apache and .htaccess completely. Notice that you must use full paths as cron jobs are ran in limited environment.
For my needs, a daily frequency (@daily or 0 0 * * *) is actually sufficient as I schedule my posts always for midnight. Those needing more precise time might decide to go hourly (@hourly or 0 * * * *) or even more often.