Setting Automatic Expiration

On every resource level (a file, a folder, a section or the whole account level) and with whichever permissions (previewer, viewer, editor), you can set the users’ access to expire at the time of cours choosing.

Just start sharing a resource by clicking on the Sharing icon and the share window appears. Choose whom to share to and toggle on ‘Expiration’.

Choose a date and time and click ‘Share’.

To modify an exisiting expiration, open the sharing window again and click on the blue clock icon next to a person or a group name to modify the time, or click ‘Clear’ in the calendar view to remove the access expiration from that person or group.

Here’s a video overview of how access expiration works.
Although it is made on single file example, the logic is exactly the same on folder, section and the whole account level.