On days when the federal government isn't doing business, neither is the post office. The U.S. Postal Service follows the same holiday schedule as federal offices.
In 2017, mail won't be delivered on Sundays, nor the following dates: Jan. 2, Jan. 16, Feb. 20, May 29, July 4, Sept. 4, Oct. 9, Nov. 10, Nov. 23, Dec. 25.
Please keep in mind that occasionally, particularly near holidays, your local post office may be open, but closes earlier in the day than usual. As New Year's Day falls on a Sunday in 2017, postal workers will not be working on Monday the 2nd.
Here's a complete list of federal holidays and the corresponding dates in 2017 when post offices will be closed:
Download the entire list of post office holidays as a PDF