With the inclusion of "Poor man's cron" in the Drupal 7 core, it is no longer necessary to set up a cron job on your web server. Instead, you can configure the frequency with which cron is run on admin/config/system/cron (Administration > Configuration > System > Cron).
Triggering Drupal cron without a cron job
With the inclusion of "Poor man's cron" in the Drupal 7 core, it is no longer necessary to set up a cron job on your web server. Instead, you can configure the frequency with which cron is run on admin/config/system/cron (Administration > Configuration > System > Cron).