Saturday is considered a working day for a post office and for the USPS.
Post offices are open on Saturday and mail delivery happens on Saturday.
However while the post office is open and delivers on Saturday, the hours the post office is open on Saturday is less hours than Monday through Friday.
Post offices close earlier on Saturday, and the actual time that the post office closes on Saturday will depend on your location.
For me the post office opens at 7:00 AM and then closes at 11:30 PM.
But the postal carrier sometimes is out delivering mail to rural areas in town until around 2:00 PM or even 3:00 PM depending on her route.
The USPS sorting facilities are open 24 hours a day, 7 days a week and even on Holidays.
USPS sorting and processing facilities remain open and operational 24/7, 365 days a year, including on federal holidays.
The mail is always moving within the system, even when local post offices are closed and regular mail delivery is suspended.
USPS sorting and Processing Facilities are large distribution centers that operate continuously to process, sort, and move mail between different locations (via trucks, planes, etc.).
This ensures that the mail does not sit idle for an entire day and helps manage the flow of mail, especially during peak seasons.
Regular Delivery & Post Offices: Local post office branches are closed on all U.S. federal holidays, and there is no regular residential or business mail delivery.
Letter carriers and window clerks generally have the day off.