You can choose to schedule your campaign for a later date in the final step of your campaign set up.
From the Review & Edit page click on the Schedule Delivery button at the bottom of the page.
Your local time zone is automatically selected but you can change this if you want to.
Choose the date and time you would like to send your campaign out. When your campaign has been sent, you will see it in the campaign page.
The scheduling tool is only available for subscribed customers.
Further Reading: