Cron jobs are scheduled tasks that are run by the operating system at specified times.  eDirectory uses them to expire listings, send renew reminders, roll up traffic reports and do other system maintenance.

Below is an overview of the required Cron Job schedules for Version 9.1:
 
cron_manager.php // needs to be scheduled to run every 5 minutes (it manages a queue for all the other crons), here is the list of the crons that it manages:
 
email_traffic.php // sends the stats of the listings to the listing owner
renewal_reminder.php // sends an email to remember the listing owners about the listing expiration
randomizer.php // generates a random number for all the listings (used to determine the order of the listings at the 'featured' box)
daily_maintenance.php  // expires the listings
report_rollup.php  // generate stats
statisticreport.php // generate stats
sitemap.php // generates the sitemap.xml for the crawlers and the sitemap.php for human visitors
location_update.php // updates the relanshionship of the locations
export_listings.php // export listing functionality
export_events.php // export listing functionality
 
* if you prefer you can schedule each of the crons individually and 
not schedule the cron_manager, but this is not recommended
////////////////////////////////////////////////////////////////////////
 
Crons that need to be scheduled individually :
 
listing import functionality crons :
 
import.php // runs the import facility for listings
prepare_import.php // prepares import files that have more than 1000 listings
 
events import functionality crons :
 
import_events.php // runs the import facility for events
prepare_import_events.php // similar to the listings one
 
////////////////////////////////////////////////////////////////////////
* none of the the count_* crons needs to be scheduled
* populate_dashboard.php also doesn't need to be scheduled
////////////////////////////////////////////////////////////////////////
 
Example of cron lines with the cron_manager :
////////////////////////////////////////////////////////////////////////
* Please don't forget to replace [path] with the current path in your server
  for example :
  /var/www/html or /home/account/www
////////////////////////////////////////////////////////////////////////
 
*/5 * * * * [path]/cron/cron_manager.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/prepare_import.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/rollback_import.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/import.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/prepare_import_events.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/rollback_import_events.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/import_events.php 1>&2>> [path]/cron.log
 
Example of cron lines without the cron_manager :
////////////////////////////////////////////////////////////////////////
* Please don't forget to replace [path] with the current path in your server
  for example :
  /var/www/html or /home/account/www
////////////////////////////////////////////////////////////////////////
0,20,40 * * * * [path]/cron/renewal_reminder.php 1>&2>> [path]/cron.log
10,30,50 * * * * [path]/cron/randomizer.php 1>&2>> [path]/cron.log
0 3 * * * [path]/cron/daily_maintenance.php 1>&2>> [path]/cron.log
5 0 * * * [path]/cron/report_rollup.php 1>&2>> [path]/cron.log
0 20 * * * [path]/cron/sitemap.php 1>&2>> [path]/cron.log
5 0 * * * [path]/cron/statisticreport.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/export_listings.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/export_events.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/location_update.php 1>&2>> [path]/cron.log
* * * * * [path]/cron/import.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/prepare_import.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/rollback_import.php 1>&2>> [path]/cron.log
* * * * * [path]/cron/import_events.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/prepare_import_events.php 1>&2>> [path]/cron.log
*/5 * * * * [path]/cron/rollback_import_events.php 1>&2>> [path]/cron.log
25 1 * * * [path]/cron/email_traffic.php 1>&2>> [path]/cron.log