Scheduling review of content I have a content type that includes a date field called expires.  I'd like to set up some way to monitor all nodes of this content type and if the current date is close to the expires field value, send an email.  I checked the rules module using the built in scheduler, but I didn't see a way to check a specific node, or a series of nodes.
Use hook_cron() to check the value of that field when cron runs and fire off an email with drupal_mail_system() if the value meets your criteria.