On the literary and scholarly awesomeness of the timezone file

Jon Udell's "A literary appreciation of the Olson/Zoneinfo/tz database" points out the transcendentally complex nature of keeping track of every timezone and temporary change in times that exists today or has existed in the past. I've spent hours poring over this file and have to concur with John -- it's probably the most fascinating reading on your hard-drive.

What I didn't appreciate, until I finally unzipped and untarred a copy of ftp://elsie.nci.nih.gov/pub/tzdata2009o.tar.gz, is the historical scholarship scribbled in the margins of this remarkable database, or document, or hybrid of the two.

You can see a glimpse of that scholarship in the above example. The most recent two rules define the latest (2007) change to US daylight savings. The spring forward rule says: "On the second Sunday in March, at 2AM, save one hour, and use D to change EST to EDT." Likewise, on the fast-approaching first Sunday in November, spend one hour and go back to EST.

But look at the rules for Feb 9 1942 and Aug 14 1945. The letters are W and P instead of D and S. And the comments tell us that during that period there were timezones like Eastern War Time (EWT) and Eastern Peace Time (EPT). Arthur David Olson elaborates:

From Arthur David Olson (2000-09-25): Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama. In the introduction, Oboler spoke of "Eastern Peace Time." An AltaVista search turned up :"When the time is announced over the radio now, it is 'Eastern Peace Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."

Most of this Talmudic scholarship comes from founding contributor Arthur David Olson and editor Paul Eggert, both of whose Wikipedia pages, although referenced from the Zoneinfo page, strangely do not exist.

A literary appreciation of the Olson/Zoneinfo/tz database

• [Little John]

  Interesting stuff; thanks, Cory.

  And that’ll be Jon Udell, not John.

  Love, John

• [Roy Trumbull]

  During the war the time signal, usually near the top of the news would be, “6 o’clock eastern war time” for New York etc.. During that period and after, the time signal was sold to the Bulova watch company. It’s 6 o’clock B-u-l-o-v-a Bulova watch time.
  Every product had a war angle. “Lucky Strike Green went to war.” Their logo was green instead of red during the war.
  When you bought a loaf of bread several bakeries offered a plane spotter wheel so you could match a plane’s outline against our planes or the enemies.
  And every kid had a mini military dress outfit to match the service their dad was in.

  • [No Imagination]

    Lucky Strike’s logo has always been red. The package itself was green before the war, and was changed to white so the dye/ink/coloring agent could be used in camoflauge paint. Thus, the “green” went to war.

• [PaulR]

  Obligatory link:
  Sir Sandford Fleming’s Heritage Minute:
  http://www.histori.ca/minutes/minute.do?id=10182

• [Roy Trumbull]

  Something I really don’t know is how network time tracks leap seconds. The earth as a clock wanders about whereas the cesium atom is very steady. Leap-seconds bring them in sync. But I don’t know if network time leaps or is averaged over an interval. Geek-Meisters what say you?

  I once had an electronic master clock than I could manually advance. But the impulse clocks it drove took hours to get right. Now, with GPS, systems are easier to sync.

  • [sabik]

    Leap seconds are applied in the underlying UTC time tracking, at least on Unix-like systems, well before the timezone information is applied. For most practical purposes, of course, it doesn’t matter, but standards like POSIX and programs and protocols like NTP do handle them (but not in the same way). The actual handling is rather an afterthought; see http://en.wikipedia.org/wiki/Unix_time

• [Anonymous]

  No wikipedia pages? Once they had completely mastered time, they probably ported themselves into an alternate utopian timeline, thus erasing traces of their existence here — except for echoes of their original work with time, such as the timezone file.

• [sla29970]

  Leap seconds are handled inconsistently because international agreement specifies the use of mean solar days (and seconds) whereas technological operation demands the use of atomic seconds. The legal ramifications of those two produce this curious discrepancy.