In Events Planner, the recurrence helper is used for two purposes.
1) Creating dates in the dates section using the Recurrence Helper
To automatically create dates for the event.
To construct a class schedule for the Class/Course event type
In the Dates meta box, expand the Recurrence Helper section by clicking on the + icon. Enter and select the appropriate values and simply click on the “Preview Calendar” button to see a calendar representation of the dates. Once you are happy with the preview, click on the “Get Date Fields” button to get the dates section populated based on your formula.
2) Using the Recurrence Helper to crate a class schedule
Please see class type page for more info.