The U.S. Postal Service expects to deliver approximately 15.5 billion cards, letters, flats, and packages this holiday season. In addition, they are projecting approximately 600 million packages will be delivered between Thanksgiving and New Year’s Eve, which is an increase of 10.5 percent from last year.

Following the success of the 2014 holiday season, the Postal Service will again deliver packages seven days a week in select major cities and high-volume areas beginning Nov. 29, for the four Sundays before Christmas. They expect to deliver on average approximately 5 million packages every Sunday during December.

The Postal Service predicts Dec. 14 will be the busiest mailing and shipping day. The busiest mailing day also is expected to be the Postal Service’s busiest day online with more than 7 million customers predicted to visit usps.com.

Dec. 21 is expected to be the busiest delivery day for holiday packages, cards and letters. The Postal Service anticipates that more than 30 million packages will be delivered that day alone.

For delivery in anticipation of Christmas, the Postal Service recommends keeping the following mailing and shipping deadlines in mind:

Nov. 7 – APO/FPO/DPO Standard Post
Dec. 8 – Priority Mail Express International
Dec. 15 – Standard Post
Dec. 19 – First Class Mail
Dec. 19 – Global Express Guaranteed
Dec. 21 – Priority Mail
Dec. 23 – Priority Mail Express.