I think the major element in "that day" shipping from the west coast to the
east is the sun.  East Coasters are at home eating dinner at least 3 hours
before the West.

You can also save a day (UPS ground) if you are near one of these places:

Louisville, Ky.;
Philadelphia, Pa.;
Dallas, Texas;
Ontario, Calif.;
Rockford, Ill.;
Columbia, S.C.;
Hartford, Conn.

> It is easier for a West Coast company to get something out "that day"
> than it is for an East Coast company. This may be more or less true
> depending on whether you are near a hub or not (for the carrier you are