The Approval and User Input steps can be configured to expire either after a specified delay, or on a specific date.
IMPORTANT: The Expiration feature uses the WordPress Cron. This is usually activated by default on most installations, but if you host has disabled it you may need to ask your administrators to enable it.
The Status after expiration setting allows you to define the status of the step after the expiration period has elapsed. If "Expired" is selected then a "Next step if Expired" setting appears allowing you to route the workflow to a different step. This is useful for implementing escalation processes which need to happen if action is not taken within a defined period.