On December 18, 2018, U.S. President Donald Trump signed an Executive Order declaring December 24, 2018 a Federal Holiday. U.S. Customs and Border Protection (CBP) stated in Cargo Systems Messaging Service (CSMS) #18-000751 that they will operate as a holiday and “[s]elf-filers and brokers should plan CBP-related business accordingly.”
CBP stated that filers can present or pay on Wednesday, December 26, 2018 without penalty.
The CSMS may be found here:
https://csms.cbp.gov/viewmssg.asp?Recid=23962&page=&srch_argv=&srchtype=&btype=&sortby=&sby=