To edit the scheduling of the alert do the following:
Save the search as a report (or alert)
Go to settings > searches, reports and alerts
Click on the name of the report/alert
Check the box "Schedule this search"
The first option should be how frequently you run the report/alert. Schedule type is either basic or cron. If you select basic it will give you options such as "every minute" or "every hour". If you select cron, you will be allowed to enter the exact cron format of how you want the job to run.
Hope this helps
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