Does Anybody Really Know What Time It Is?

Does anybody care? Time engineers do

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Regular listeners will notice a new name for this podcast—Techwise Conversations. The show will soon have a phone and tablet app for iOS and Android, so we’re taking the opportunity to rename it as well.

Every four years, we adjust our calendars by one day. An entire day is a big deal.

Twice a year, we in the U.S. adjust our clocks by one hour. An hour is a big deal.

Twice in the last six years, the world’s timekeepers have changed our clocks by one second. And I bet you didn’t even notice, because a second is no big deal.

Unless you’re an airline pilot. According to an article in the current issue of Communications of the ACM, a plane moves 300 meters in one second. A one-second hiccup in the radar of an air traffic control system is not a trivial matter.

Back in December, a 70 millisecond power glitch at a Toshiba semiconductor facility resulted in massive losses, and output was down 20 percent for the next two months.

Computers are all about numbering and measuring everything, so you would think that as we get more computerized, we’d be all the more prepared for leap seconds. But the reverse seems to be the case.

There are no standards for how to plan and manage leap seconds, and most systems go down for planned maintenance instead of trying to deal with leap seconds in real time. The U.S. nuclear arsenal is reportedly put in a so-called special mode for one hour before and after a scheduled leap second.

My guest today, who authored that article in Communications of the ACM, thinks it’s high time we figured out what to do with leap seconds.

Poul-Henning Kamp is an independent software developer and a longtime and prolific contributor to open source software, to Internet protocols and standards. He also maintains the principal network time servers for his homeland, the nation of Denmark. Time seems to be in his blood—he’s also the author of Varnish, a popular web accelerator that runs under the hood of many of the Internet servers we use.

He seems to be having a lot of fun along the way—he invented the Beerware License and also the phrase “bikeshed color,” which describes, as Wikipedia puts it, “contentious but otherwise meaningless technical debates over trivialities in open source projects.” He also had to veto the first date and time I suggested for this interview because he was already scheduled to be busy restoring a 50-year-old computer at the Danish Computer History Association.

This interview was recorded 10 May 2011.
Audio Engineer: Francesco Ferorelli
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