1. Logged in as an Administrator, enter setup, and search for "Apex Classes" in quick find box.
2. From Apex Classes select the "Schedule Apex" button.
3. On the Schedule Apex Screen, enter the Job Name as "iATS Nightly Download", and search for the Apex Class called "iATSPayments_journal_log"
4. Set the "Schedule Apex Execution" schedule as shown below.
5. Save.