Deadlines are important. Both brands and influencers have schedules and objectives for social media and it's important that both parties respect each others time. However, life is never perfect and in some instances the deadline might need to be updated to accommodate for unforeseen circumstances.
The deadline can be updated in the agreement by simply clicking on OPEN AGREEMENT from the right hand sidebar and then on EDIT AGREEMENT. From here you can adjust the time accordingly.
If a product is being shipped, the deadline will be based upon X-days after its arrival date with the influencer. If no product is being shipped then an actual date can be selected from the calendar.
Typically 7 days is sufficient time, but you should also take into account the scope of the agreement (i.e. a video may take more time than a static Instagram post).