Why doesn't UPS deliver all night long?
UPS packages are sorted and routed through a facility called Worldport in Louisville, Kentucky [1]. From midnight to 8 AM, a plane lands at Worldport every 60 seconds and 130 planes arrive every day [1]. Once packages arrive, they go through a complex web of automated conveyer belts [1]. An employee then loads the packages into one of UPS's 38 thousand shipping containers that go onto the plane [1]. These packages can be delivered anytime between 9 AM and 7 PM during weekdays and Saturdays [2]. Since the delivery times are not specified, packages may be delivered up to 8:00 to 9:00 PM [2].
UPS does not deliver on Sundays because there is not enough demand for Sunday delivery for it to be profitable. UPS makes its profit on business-to-business shipments, and most businesses are closed on Sundays. Therefore, UPS makes less profit on business-to-residential shipments. [2] UPS also delivers packages as late as 7:00 pm or sometimes later, up to 8:00 to 9:00 pm. [1]