USA.gov — Starting in August, the U.S. Postal Service will no longer deliver regular mail to street addresses on Saturdays. Mail will be delivered Monday through Friday.
The following services will NOT change:
- Packages will still be delivered on Saturdays.
- Mail will still be delivered to PO Boxes on Saturdays.
- Post Office locations currently open on Saturdays will remain open on Saturdays.
Discontinuing Saturday delivery is expected to save the Postal Service $2 billion annually.
The Postal Service is an independent government agency and does not receive tax money to support its operations. It relies on the sale of postage, products, and services to fund its operations.
If you would like more information about the new mail delivery schedule, you can send questions and comments to the U.S. Postal Service.
Pierce Prairie Post 
There is an excellent article at this link on how the lame duck Republican Congress and President in 2007 passed and signed into law a mandate requiring “pre-funding” of retirement benefits at the Postal Service. This was intentionally to “break” the US Postal Service. Keep in mind, these are the folks that want everything privatized, so ending the “monopoly” the Postal Service had was a step toward that end. Since the US Postal Service has always been self supporting, this explains what Congress did to hurt it financially.
http://www.thestand.org/2013/02/congress-broke-usps-and-now-must-fix-it/