You can change the launch time of a campaign any time before it begins even if it has been confirmed. All campaigns are now located in the campaign list.
1. Locate the Campaign
Go to the campaign list, find the one that you want to reschedule
2. Click on the View Details button.
This will take you to the campaign detail view.
3. Scroll to the Notification and Campaign Schedule Section
4. Update the Start Date
When you update the start date, you will be asked if you want to reset existing campaign notifications to the default set.