If the job was created by a policy, you must first click Delete jobs created by policy in the Job Setup task pane, and remove the association between the policy and the selection list. Then, you are prompted to delete the jobs that were created when the policy and selection list were combined.
To delete a scheduled job
To delete only the occurrences for a specific date, click Cancel on the warning message. On the navigation bar, click Job Setup and then right-click the job. Click Properties, and then under Frequency on the Properties pane, click Schedule. Click Run according to schedule, click Edit Schedule Details, and then exclude that date.
After clicking Delete, you are prompted to delete backup selection lists that are no longer in use by any other jobs. Click Yes to delete all of the unused backup selection lists, or click No to leave the backup selection lists intact.