This holiday season, the United States Postal Service expects to deliver roughly 15.5 billion cards and letters and 600 million packages. The deadline to get letters and packages out in time for Christmas is fast approaching.

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FedEx needs packages by Wednesday for standard ground delivery.

UPS needs packages by Friday.

First class mail has a deadline of Saturday.

Keep in the mind that earlier is better -- a recent study says holiday deliveries are taking longer this year. Based on research from Cyber Monday orders, packages took an average of 6.9 days to be delivered. That number is 20-percent slower compared to 2014, FOX Business reports.