In the Section Name field [1], create a name for the section.
If you have permission to view the SIS ID field [2], add an SIS ID or edit an existing ID.
Create a start date for the section by clicking the Starts calendar icon [3]. Create an end date for the section by clicking the Ends calendar icon [4].
If you want the section participation dates to override the course dates, select the Users can only participate in the course between these dates checkbox [5]. Any user added to the section won't be able to participate in the course until the section start date.
Click the Update Section button [6].
Note: Unlike when changing course dates, currently the User Participation checkbox in sections enables the override for the section.