Effective Monday, April 6, 2020 due to a significant reduction in privately owned vehicle and pedestrian traffic along the northern border, the U.S. Customs and Border Protection (CBP) will temporarily reduce the hours of operation at the Port of Porthill, Idaho. The new temporary opening hours will be 7 a.m. to 5 p.m., seven days a week.
Read the full news release here: https://www.cbp.gov/newsroom/local-media-release/cbp-temporarily-reducing-hours-port-porthill-idaho 
At this time, there are no changes to the hours of operation for entry into Canada at Porthill as per the Canada Border Services Agency (CBSA).