The United States Postal Service has announced its Holiday 2016 shipping deadlines to ensure customers can get gifts, letters, cards and packages to their destinations on time for the holiday season. If shipping domestically, senders should have their package in by Dec. 15 if using USPS Retail Ground, Dec. 20 with First-Class Mail, Dec. 21 with Priority Mail and Dec. 23 for Priority Mail Express. The USPS uses Dec. 25 as the date most costumers would want their packages delivered by. A full list of domestic and international dates can be found by following the link included below this story.