USPS: December 13-18 will be the busiest mailing, shipping, and delivery week of the year.

Customers can ship their packages through USPS’ Retail Ground service by Wednesday, December 15, so they arrive by Christmas Day.

If you are interested in using their First-Class Mail service, USPS encourages those to get to the post office by Friday, December 17.

Christmas gifts traveling via Priority Mail will need to be sent by Saturday, December 18.

The last date to use the USPS for gifts this Christmas season is Thursday, December 23, which is the deadline of their Priority Mail Express service.