Ideally, the package will be shipped on the date on the label. If the date has passed, this can interfere with the timeframe required to deliver a shipment. Carriers may accept packages within a couple of days past the ship date on the label, but we cannot guarantee that all locations and carriers will allow this. We recommend setting the Ship Date to the date that you actually plan to ship the package.
When you create a label, the Ship Date automatically populates with the current date or the next shipping date. This can be manually overwritten with a date of your choosing by including a “ship_date” parameter in your request.
Please note: On national holidays when USPS is closed, ShipEngine may automatically set the date forward to the next USPS business day.