PBS: Timekeeper No More

With so many other ways to set the time on electronics, there's little need to rely on the local public broadcaster anymore

by Stephen H. Wildstrom

Michael Wilson still uses a video cassette recorder but is having trouble setting the time:

While I love my TiVo (TIVO), I still sometimes record things on my VCR—say, the entire Oscars show, even though it has a low probability of actual replay. Everything worked fine until the recent change to daylight savings time. That change did not happen on my VCR. The Public Broadcasting Service (PBS) has a contract for providing the extended data signals for all automatic time-set VCRs. It used to be very accurate. I contacted my local PBS station and they apologized. They changed the time, but made it three minutes and 14 seconds fast. A subsequent contact has had no result. Neither has an e-mail to PBS. Does anyone else care? I'd love my VCR to go back to the old reliable accurate time.

The public broadcasting transmission of time signals has become something of an orphan technology, largely because there are now so many other sources for time information and because the main users, VCRs, have been retreating into obscurity. Still, that's no excuse for the station that is putting out the time signal to not get it right.

All of these time signals in the U.S. ultimately come from the atomic clocks at the nation's official timekeeper, the National Institute of Standards & Technology (NIST). The PBS signals had a pretty short useful life, since they only came into fairly widespread use toward the end of the VCR era.

Digital video recorders either get their time from the cable or satellite network to which they are connected or from the Internet, using Network Time Protocol, the system that keeps time synched for network-connected computers.

Special radio clocks pick up their time from signals broadcast by NIST. In general, time signals are sent out as Universal Time Coordinated, which is almost, but not quite, the same as Greenwich Mean Time. It is the responsibility of each device to correct for time zone and the presence or absence of daylight time. The one exception is mobile-phone handsets, many of which get both time and time zone information from the wireless network.

When all else fails, which seems to be the case with your VCR, you'll need to set the time the old-fashioned way: manually.

Wildstrom is Technology & You columnist for BusinessWeek. You can contact him at techandyou@businessweek.com.