How to Set an Expiry on Your Form
By default your form is published forever unless you unpublish it manually or set an expiration date.
Access the form you wish to change (How to Access a Form).
Navigate to the ‘Publishing’ tab in the middle panel
In the top of the right panel you will see a 'Start Date' and an 'End Date'
Use the ‘End Date’ to set a day and time your form will become unavailable.
Form changes will be saved automatically.