Setting up reminders is very simple. You simply have to run the {{reminders.php}} script in your {{/horde/kronolith/scripts/}} directory on the shell. To do it manually, simply try this (replace {{/var/www/horde}} with the path to your Horde installation):
php /var/www/horde/kronolith/scripts/reminders.php
Note: Your {{php}} executable must be the CLI version, it will NOT work with the CGI version. Do {{php -v}} to verify that you have the CLI version.
If this works (you will get an email), you have to create a cronjob to call the reminders skript regularly. In this example, it is called every five minutes. So edit your crontab:
crontab -e
and enter the following (replace {{/var/www/horde}} with the path to your Horde installation and {{/usr/bin/php}} with the path to your PHP CLI binary):
Kronolith reminders
*/5 * * * * /usr/bin/php /var/www/horde/kronolith/scripts/reminders.php