To create a new schedule, please navigate to Manage > Schedules. Here you will need to click the "Create Schedule" button to add a custom schedule to your Backup Radar portal.
In this example we will explore the creation of a schedule for the last Saturday of every month.
To achieve this we will need to create 3 separate schedules:
The first we need to create is specifically for February as the number of days is 28.
Secondly, we will need to create a schedule for the 30 day months.
Finally we will need to create a schedule for the 31 day months.
All three of these schedules will need to be assigned to the desired backup(s), for Backup Radar to only expect results on the final Saturday of each month.
For more information on how to assign a schedule, please see this article.