I find USPS wildly uneven. It’s like the poem about a little girl: “When she’s good, she’s very good, but when she is bad, she is horrid.” Domestic cards can take anywhere from two (business) days to two weeks. My post office engages in the nasty trick of some Out for Delivery mail not loaded on the truck, so to clear that they scan it as Delivered in the post office building before the end of the day instead.
The employees themselves are mostly very nice, trying to do their best. In the 2.5 years I’ve lived here, I’ve had three or four items that were for a neighbor, and the same vice-versa. Delivery time is usually late afternoon, so am envious of folks in countries where theirs seems to arrive in the morning. Earliest I’ve noticed has been a few times around 1 PM (13.00), while 6 PM or so (18.00) has happened a few times.
It seems to take about a week for incoming international mail to get to me once the plane lands in USA. Our sorting machines, unfortunately, do a lot of damage!