USPS generally delivers packages until around 5 PM local time on most days. However, delivery times can extend until 6 PM or later depending on busy periods, weather, or other delays. During peak seasons like holidays, deliveries may continue as late as 8 PM or beyond. On Saturdays, deliveries can occur as late as 7 PM, and on Sundays, Priority Mail Express and Amazon packages may be delivered until about 6:30 PM. Nighttime deliveries (even up to 9 or 11 PM) are rare but possible during high demand or delays. These times can vary based on location, route, and daily mail volume.