In the rule's time configuration, there are settings for Periods and Steps.
The steps are relevant for resources of type Rental.
Periods can be repeated in time according to different rules.
To set up a recurrence of a particular period, click on it.
Then specify how to repeat.
You can also edit all or several periods.
To do this, select the periods and click Edit.
The period configuration form opens.
Select Custom settings to see all recurrency options.