We've done some work on this - we wanted automatic time-keeping for our parking equipment.
I did a simple decoder (in QBasic) for the German DCF77 signal (we're in Belgium). The decoder chips work with different standards, so maybe the US one is there too.
Basically, you get a beep or a bip each second (like Morse code?! there's nothing new!), with 1 sec silence to mark the minute. Once decoded, you've got the date & time. We loggged the summer/winter time-change with the deal, just to see. No final product tho.
When I'm back at work tommoroow (23:15 CET here!), 4ll find the specs of the chip we used.

Bye for now,

R

BTW the receiver ferrite antenna has to be at least 2 meters from your PC, else it get drowned by the cpu clock & other stuff!