In Pirate Ship, you can change your Ship Date and when your Tracking Emails will be sent.
USPS allows you to set your ship date for up to 7 days into the future.
To schedule your Ship Date, fill out the recipient's information and package details and click GET RATES. Before you click BUY LABEL, click the calendar icon and select your ship date:
USPS usually allows you to ship your package as long as the Ship Date is within a few days of when you actually hand them the package... however, it is at each employee's discretion. They can technically refuse to ship your package if you wait too long! Best practice is to get your package into the mail stream as close to the postmarked date as possible.