As an administrator, you can change the deadline for signing an interview campaign.
To do this, go to your Manager Area > Interviews > Interview Tracking.
Select the campaign for which you want to change the signing deadline by clicking on the corresponding card.
The three little dots at the top right of the page will allow you to access the action button "Edit Campaign".
You can then edit the "Signing Deadline" field to select the new date you wish to set before saving your changes.