If you previously set a submission deadline for your form, you can extend or remove the submission deadline date for the form. To do this:
From your forms page, click on the Settings option for the form you would like to change the submission deadline or navigate to the Settings tab in the form builder when editing your form.
On the Basic tab (default opened tab), click on the Submission Deadline field/option to remove or change the date to another date, then click on the Save Options button when you are done with the changes.
Please note that the form will stop receiving submissions from 11:59 pm of the set date based on your time zone.