The Daily Parker

Politics, Weather, Photography, and the Dog

2012 will be even longer

The Paris Observatory has announced a leap second between June 30th and July 1st this year:

A positive leap second will be introduced at the end of June 2012. The sequence of dates of the UTC second markers will be:

   2012 June 30, 23h 59m 59s
   2012 June 30, 23h 59m 60s
   2012 July  1, 0h  0m  0s

... Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the [available rotation data].

Leap seconds occur from time to time because the earth's rotation on its axis doesn't stay exactly the same from year to year. Most years it loses about half a second; the last couple of years it hasn't lost as much, so the last leap second came just before 1 January 2009. Eventually, the earth will stop rotating on its axis relative to the sun, in much the same way the moon rotates once on its axis every time it orbits the earth. You've been warned.

This has an interesting side effect, by the way: UTC is now 34 seconds behind the earth, so clocks on things like orbiting satellites—think GPS—have "incorrect" values. Your hand-held GPS receiver will probably be a second slow after June 30th. Your computer, if it syncs up to an authoritative time service, won't.

Chicago sunrise chart, 2012

Welcome to the semi-annual update of the Chicago sunrise chart. (You can get one for your own location at

Date Significance Sunrise Sunset Daylight
4 Jan Latest sunrise until Oct 28th 07:19 16:33 9:14
28 Jan 5pm sunset 07:07 17:00 9:52
5 Feb 7am sunrise 07:00 17:11 10:10
21 Feb 5:30pm sunset 06:39 17:31 10:52
27 Feb 6:30am sunrise 06:30 17:38 11:08
10 Mar Earliest sunrise until Apr. 15th
Earliest sunset until Oct. 27th
06:10 17:52 11:42
11 Mar Daylight savings time begins
Latest sunrise until Oct. 21st
Earliest sunset until Sept. 20th
07:09 18:53 11:45
16 Mar 7am sunrise, 7pm sunset
12-hour day
07:00 18:59 11:59
20 Mar Equinox 00:14 CDT 06:53 19:04 12:10
3 Apr 6:30am sunrise (again) 06:29 19:19 12:50
13 Apr 7:30pm sunset 06:13 19:30 13:17
21 Apr 6am sunrise 06:00 19:39 13:39
10 May 8pm sunset 05:35 20:00 14:24
15 May 5:30am sunrise 05:30 20:05 14:35
14 Jun Earliest sunrise of the year 05:15 20:28 15:13
20 Jun Solstice 18:09 CDT
8:30pm sunset
05:16 20:30 15:14
26 Jun Latest sunset of the year 05:17 20:31 15:13
2 Jul 8:30pm sunset 05:20 20:30 15:09
16 Jul 5:30am sunrise 05:30 20:24 14:53
8 Aug 8pm sunset 05:53 20:00 14:06
16 Aug 6am sunrise 06:00 19:48 13:48
28 Aug 7:30pm sunset 06:13 19:30 13:16
13 Sep 6:30am sunrise 06:30 19:03 12:33
15 Sep 7pm sunset 06:33 19:00 12:28
22 Sep Equinox, 09:49 CDT 06:39 18:48 12:08
25 Sep 12-hour day 06:42 18:42 12:00
2 Oct 6:30pm sunset 06:50 18:30 11:40
13 Oct 7am sunrise 07:01 18:13 11:10
21 Oct 6pm sunset 07:11 18:00 10:48
3 Nov Latest sunrise until 2 Nov 2013
Latest sunset until Mar 2nd
07:27 17:42 10:15
4 Nov Standard time returns
Earliest sunrise until Feb 28th
06:28 16:41 10:13
6 Nov 6:30 sunrise 06:30 16:39 10:08
15 Nov 4:30pm sunset 06:41 16:30 9:49
1 Dec 7am sunrise 07:00 16:21 9:21
7 Dec Earliest sunset of the year 07:06 16:20 9:14
21 Dec Solstice, 05:12 CST 07:16 16:23 9:07

You can get sunrise information for your location at

Short week in the South Pacific

There is no tomorrow for the island nations of Samoa and Tokelau:

At the stroke of midnight on Dec. 29, time in Samoa and Tokelau will leap forward to Dec. 31 — New Year's Eve. For Samoa's 186,000 citizens, and the 1,500 in Tokelau, Friday, Dec. 30, 2011, will simply cease to exist.

[Samoan] Prime Minister Tuila'epa Sailele Malielegaoi earlier said it would strengthen trade and economic links with Australia, New Zealand and Asia.

Being a day behind the region has meant that when it's dawn Sunday in Samoa, it's already dawn Monday in adjacent Tonga and nearly dawn Monday in nearby New Zealand, Australia and increasingly prominent east Asian trade partners such as China.

"In doing business with New Zealand and Australia, we're losing out on two working days a week," Tuila'epa said in a statement. "While it's Friday here, it's Saturday in New Zealand, and when we're at church on Sunday, they're already conducting business in Sydney and Brisbane."

The islands move from UTC-10:00 to UTC+14:00, and will therefore be the first places on earth to enter 2012.


No, not my student loan; my horological one. I might be alone here, but the return of standard time means I get the hour back that I loaned out in March. It also means I don't have to wake up before dawn any more—at least for a couple of weeks. Even Parker seems to like the "fall back." At least, he had the decency not to wake me up until 7:30am.

For most of the U.S. and Canada, today's was the earliest sunrise until February 28th. Unfortunately, today's sunset will the earliest since January 10th, as we enter the 12 or so weeks of afternoon gloom.

On the third hand (I missed my calling as an economist), Chicago's weather today is crisp and sunny, and Parker needs some walks.

Aurora forecast page

Apparently the aurora borealis came all the way down to the middle of the U.S. earlier this week. With a little probing, I found the University of Alaska aurora forecast page. Tonight, we probably won't see the aurorae in Chicago. But there's a huge sunspot right now, so possibly we'll see one later in the week.

Here's the self-updating NOAA map. The bright area shows the current aurora; the red line points to the sun.

Waking up in the dark

I'm not the only one watching sunrise times these days. Naomi the Nature Nerd also wishes we'd end Daylight Saving Time earlier:

I know that this weekend's Fall Back means I'll be coming home in the dark, instead. I'd rather just have longer days :) but given the latitude... If I have to choose, I'd choose to leave work at night, not arrive there at night!

At least this weekend won't be the latest sunrise ever in Chicago. That honor goes to 6 January 1974, when the U.S. went on Daylight Saving Time several months early in response to the 1973 oil crisis. That morning the sun rose in Chicago at 8:18.

This Saturday's sunrise will be the latest until 2016. Last year's November 6th sunrise, at 7:30am, was the latest since 1974 and will be the latest until 2021.

Of course, it could be worse. In Barrow, Alaska, the United States' northernmost city, the sun rises on Saturday at 11:37am. Barrow's latest sunrise will be November 19th, at 12:59pm—26 minutes before it sets again, not to return until January 23rd.


Correcting the record

Reader AT actually met Tom Shanks, the chief programmer behind the ACS Atlases, and corrects my understanding of how the ACS team put it together:

Contrary to what you assume in your post, Tom Shanks did not hack his atlas into an Apple II. ACS was rather professional in their IT. The worldwide city database with longitude and latitude they had licensed from on of the big atlas (map atlas) publishers, if I remember correctly Rand McNally. The timezone history data they had collected from numerous published sources..., and partly also from field research and grass root contributions by their own astrology service clients.

The reader also gave me the story about an ongoing effort to extend the tzinfo database, and the provenance of Astrolabe's alleged copyrights. (Note that this is the precise, legal meaning of "alleged:" in a civil complaint, just as in a criminal complaint, the parties "allege" each fact in their filings.) If the reader gives me permission, I'll post some of this information.

Analysis of Shanks' atlases against the tzinfo database

To better understand the facts behind Astrolabe’s stupid trolling quixotic lawsuit against the guys who coordinated the worldwide time-zone database (tzinfo), I bought copies of the Shanks Amercian and International atlases that Astrolabe claims to own. (I went through the secondary market, so I didn’t actually give Astrolabe any money.)

First, an update. According to Thomas Eubanks of the IETF, the Electronic Frontier Foundation has taken over Arthur Olson’s legal defense. Mazel tov. I expect to see a response to the complaint against him in a few weeks that includes a motion to dismiss which, I think, may be granted. (I’m thinking about drafting a response myself, just to exercise my legal muscles properly. Watch this space.)

Now to the main post. The Shanks books, rather than containing maps, contain pages and pages of tabular data showing three things:

  1. Names of first- and second-order administrative districts (e.g., states and counties);
  2. Latitudes and longitudes of cities and other named places within countries or states;
  3. Lists of the dates and times of time-zone changes for those named places.

The atlases dump this data to paper using a monospace typeface at 6-point size in what can be nothing other than 1990s-era printouts to some kind of publishing compositing software. This offers a clue to the “original works” claim that Astrolabe makes about the products.

Shanks certainly put a lot of work into these books, especially considering he first published them in 1978 and 1985. He must have spent hundreds of hours looking up and entering data on the thousands of locations in the tables.

For example, the American Atlas contains rows upon rows of data like this:

Chicago 16      1 41N51'00 87W39'00 5:50:36
Chicago Heights 16
                1 41N30'22 87W38'08 5:50:33
Chicago Lawn 16 1 41N47    87W43    5:50:52

I imagine Shanks looked up this data in reference books, then entered it into a home-grown flat-field database through a Vax terminal or on his Apple ][+. I hope he at least let the computer calculate the last column (the location’s offset from GMT), since it’s derived directly from the location’s longitude (the next-to-last column).

I imagine this because, in the early 1990s, I did something similar to study climate data. (Do you know how long it takes to enter 30 years of daily climate data by hand? No? You’re lucky.)

Back to Astrolabe’s complaint. In Count 4, Astrolabe claims ownership of “certain copyright-protected computer software programs and information contained therein…known as the ‘ACS Atlas,’ consisting of both the ‘ACS International Atlas,’ and the ‘ACS American Atlas,’ in the form of computer software program(s) and/or data bases, and in the form of electronic output and future electronic media from said programs....’ ” I infer from the complaint that the software reproduces the books in computer-searchable form, or perhaps contains the raw data that Shanks himself used to produce the books.

I’ll defer my main argument for a moment to speculate further on what parts of the tzinfo database could have copied the Shanks database.

In the tzinfo database, one of the files ( contains latitudes and longitudes of locations in this form:

US	+415100-0873900	America/Chicago	Central Time
US	+375711-0864541	America/Indiana/Tell_City	Central Time - Indiana - Perry County
US	+411745-0863730	America/Indiana/Knox	Central Time - Indiana - Starke County

Nothing else in the tzinfo database comes as close to looking like data in the Shanks atlases. I don’t know where the tzinfo list came from, but I suspect it came from public sources like the Census Bureau.

The other possible copying comes from the lists of dates Shanks put together that look like this:

IL # 1
Before 11/18/1883  LMT
11/18/1883  12:00  CST
 3/31/1918  02:00  CWT
10/27/1918  02:00  CST

Here’s how the tzinfo database shows the same information:

Rule	Chicago	1920	only	-	Jun	13	2:00	1:00	D
Rule	Chicago	1920	1921	-	Oct	lastSun	2:00	0	S
Rule	Chicago	1921	only	-	Mar	lastSun	2:00	1:00	D
Rule	Chicago	1922	1966	-	Apr	lastSun	2:00	1:00	D
Rule	Chicago	1922	1954	-	Sep	lastSun	2:00	0	S
Rule	Chicago	1955	1966	-	Oct	lastSun	2:00	0	S
Zone America/Chicago	-5:50:36 -	LMT	1883 Nov 18 12:09:24
			-6:00	US	C%sT	1920
			-6:00	Chicago	C%sT	1936 Mar  1 2:00
			-5:00	-	EST	1936 Nov 15 2:00
			-6:00	Chicago	C%sT	1942
			-6:00	US	C%sT	1946
			-6:00	Chicago	C%sT	1967
			-6:00	US	C%sT

That hot mess establishes the specific rules Chicago used to change its clocks in the 1920s and 1950s where the rules differed from the general U.S. rules, then it sets out the dates and times that Chicago’s wall-clock rule sets changed from the beginning of standard time in 1883 through the last change in 1967. (The current rule set for Chicago are the “US” rules, defined elsewhere in the database.)

Shanks has a list, and the tzinfo database has the rules to create the list. Shanks also has an error that the tzinfo database corrects: the tzinfo database establishes that Chicago switched from local mean time (LMT) to standard time at 12:09:24, because Chicago is 9 minutes and 24 seconds ahead of the standard meridian for the time zone. Shanks puts the time at 12 noon, because his list shows the target time, not the trigger time, for the rule change.

Did the tzinfo project use Shanks to determine the rules for time changes? Yes, explicitly, though for highly-documented locations like Chicago the project participants cross-referenced Shanks with original sources, often correcting his errors. But "use" does not mean "copy;" I can use all the baseball statistics I want out of the newspaper without ever copying the newspaper. Data is not protected by copyright.

The tzinfo didn’t infringe on anyone’s copyright because Shanks created very little to protect. As I’ve previously explained, facts and data do not enjoy copyright protection in the United States. Only the expression of facts does. So if the tzinfo project had photocopied Shanks’ atlases, or republished the ACS software wholesale, then perhaps there would be an infringement. But I think I’ve shown a bit of why the tzinfo project hasn’t done anything actionable.

The Shanks atlases are like meticulously hand-copied illuminated codices from the 16th century, years after Gutenberg made his Bible and made hand-copying obsolete. I’m glad Shanks did the work; I’m sure he felt like he’d accomplished something huge. I really admire the work that went into it, while at the same time shaking my head at the wasted effort. Because since the late 1990s, all that data—latitudes, longitudes, place names—has been available for free from the Census Bureau and the CIA.[1] Before around 1998, you couldn’t just download the data through FTP for free; you had to write a letter to the appropriate agency and pay for it. But being U.S. government data, it was in the public domain, so once you’d paid for it, you could republish it in an easier-to-use form and recoup royalties.

In an era before the Census Bureau started dumping terabytes of data to the Internet, Shanks’ atlases would have been incredibly convenient sources of geographic and time-zone data. Today, they’re curiosities, monuments to exactly the kind of mental effort obviated by fast, cheap computers and the Internet.

Poor Shanks, all those data, thousands of rows of it, standing nakedly, and often erroneously, on page after page of tables in two massive volumes, apparently not knowing that he could have gotten it from the U.S. government—you have to admire that work ethic.

Astrolabe, for its part, has degenerated into exactly the kind of mental deficiency reviled by those of us who actually create software for a living. I eagerly await their much-deserved legal defeat in the next few months.

[1] Yes, the CIA publishes tons of free data, from their World Factbook to entire databases of geospatial information.

Edited at 20:58 UTC: Clarified the difference between "use" and "copying."

Simplified explanation of tzinfo mess

The AP has picked up the story about the tzinfo database moving to ICANN:

The organization in charge of the Internet's address system is taking over a database widely used by computers and websites to keep track of time zones around the world.

The transition to the Internet Corporation for Assigned Names and Numbers, or ICANN, comes a week after the database was abruptly removed from a U.S. government server because of a federal lawsuit claiming copyright infringement.

Without this database and others like it, computers would display Greenwich Mean Time, or the time in London when it isn't on summer time. People would have to manually calculate local time when they schedule meetings or book flights.

Ah, I do love the popular press, trying to explain things. AP writer Anick Jesdanun generally did all right explaining the problem and the move, except the story has no information about the tzinfo community's response to the mess. (I'm just sad they didn't mention The Daily Parker.)