Is the intent to get an accurate time fix by radio or some other portable device?
If so, a shortwave reciever would be a good thing to have. Many goverments offer time and frequency stations that you can recieve.
Land line telephone connections within a country generally have less than 30 milliseconds delay. Most governments also offer a dial-in for the time service. This method is probably the most accurate for the average person trying to get the *correct* time.
Another method would be a GPS reciever as the technology is based on time delay from signals from GPS satellites, each of which carries a cesium atomic clock.
But if you're asking about actual audio delay on radion for other reasons, Squiggy is correct.
As a side note, the NBC TV network in the US recently added a 4 second delay in delivery to local affiliates. It'll be interesting to see how new years eve is handled for 2010.
Here are some methods in the US for checking the time.
NIST station WWV- 2.5, 5, 10, and 15 Mhz AM Shortwave.
WWV phone access- 303-499-7111
http://tf.nist.gov/stations/wwv.html
US Naval Observatory time- 202-762-1401