Do UPS packages move at all on Saturday and Sunday?
Saturday, yes: UPS runs both pickup and delivery on Saturday for residential and commercial parcels. Sunday, no: UPS's own weekend page states there are no pickups nor deliveries on Sunday, which covers the customer-facing side of the network completely.
Why is my UPS tracking page frozen from Friday night to Monday morning?
Because the visible scans are tied to specific events: a package departing one facility or arriving at another. If a parcel is sitting between those events, or waiting for the next scheduled sort, no new scan is generated, and a silent tracking page over a weekend usually means exactly that rather than a lost shipment.
Can I still drop a package at UPS on a Sunday?
Yes, into a drop box, which UPS lists as available 24/7. The parcel simply waits for the network's next scheduled collection rather than being lost or ignored; a Sunday-evening drop and an early-Monday drop reach the same point in the process.
Does dropping a package off Friday afternoon cost a day compared to Friday morning?
It can. A parcel handed over after that location's collection cutoff is not picked up until the next business day it's staffed, which for many UPS locations means Monday. The transit clock generally starts from the day the carrier actually takes possession, not the day it was dropped off, so a late Friday handoff and an early Monday handoff can produce the same start date.
Is a stalled tracking page on a weekend the same as a lost package?
Not by itself. A quiet Saturday-to-Monday stretch on a package that had normal scans through Friday is the ordinary pattern for a shipment waiting through the part of the week UPS does not run residential delivery. A package worth investigating is one with no scans at all since drop-off, on any day.