"48 Hours" -- What does the title mean?

I just turned on “48 Hours” and it occurred to me … 48 hours of what? “60 Minutes” is an appropriately descriptive title, but I can’t figure out what happens on “48 Hours” when the clock strikes 48 hours and one second. Do the reporters stop reporting?

As I recall, originally the reporters took one story and followed it for 48 hours. That’s changed, of course.

StG

^^^ What he said. The show started off following the object of the story - say overworked NYC ambulance drivers - for 48 hours. Obviously, this is no longer the case, just as “Nightline” is no longer about the Iraninan hostage crisis.