Although packages are shipped through UPS on Saturday through their distribution centers Saturday is not considered a business day for UPS.
But the people in the distribution centers for UPS are usually at work sorting packages and putting them on the trucks and semi trucks and airplanes for the UPS packages to be delivered on Saturday.
UPS does deliver some packages to residential addresses on Saturday but only if you pay for Saturday delivery for packages that are shipped through UPS next day or second day air shipping.
But normal packages are not delivered on Saturday through UPS.
So if it's Friday and you haven't received your package then you will have to wait until Monday to get your package.