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 2022, mail won't be delivered on Sundays, nor the following dates: Jan. 1, Jan. 17, Feb. 21, May 30, July 4, Sept. 5, Oct. 10, Nov. 11, Nov. 24, and Dec. 26. (Because Christmas falls on Sunday, the next day will be treated as a postal holiday.)
Please keep in mind that occasionally, particularly near holidays, your local post office may be open, but closes earlier than usual.
Here's a a complete list of federal postal holidays and the corresponding dates in 2022 when post offices will be closed:
Download the entire list of post office holidays as a PDF