Postal ServiceDec. 14: USPS Retail Ground shipments ✅Dec. 18: Alaska to mainland First-Class Mail ✅Dec. 19: Hawaii to mainland First-Class Mail and Priority Mail, also Alaska Priority Mail ✅*There’s still time for dates below! Dec. 20: First-Class Mail ServiceDec. 21: Priority Mail; Also deadline for Alaska and Hawaii to the mainland through Priority Mail ExpressDec. 23: Priority Mail ExpressTrying to send something overseas or to a member of the military? Click or tap here to check out the guide we followed from USPS, and to learn more about your mailing specifics and guidelines. FedExDec. 9: SmartPost ✅Dec. 16: Ground and home delivery ✅Dec. 19: Express Saver ✅*There’s still time for the dates below! As for Amazon deadlines, you’re likely looking at Dec. 22 or Dec. 23, depending on if you’re a Prime member, where you live and what you’re ordering.