Amazon buy shipping, UPS ground or overnight services being the only ones available for standard shipping?

[TheOrangeCrush]

@Amazon_Seller

It’s closed Saturday, but it’s open Monday, the deliver by date. Even though the post office is closed on holidays, it’s still moving between facilities.

The system is counting both Friday and Saturday as postal holidays where nothing will be delivered or moving through the system. The programmers are incompetent. What else would you expect?

FYI - USPS Site is not fully Ground Advantage Integrated

Why is it that ground advantage is only offered for items under 1 lb? Every time I enter anything over 1 lb, only Priority mail is offered. Is this an Amazon glitch?