Hi just B you,
Thanks for writing in! As a seller you can set a processing time. When that date passes the ability to purchase a shipping label no longer exists. For each order, you will have one opportunity to edit the “ship by” date.
You can learn more about processing times and "ship by" dates here:
http://www.etsy.com/help/article/3153 I hope that helps but, if you have any other questions about shipping labels, you may also want to check in with the Shipping Labels Improvements team for more info.
Have a great day!
Heather
Etsy's Payment Support