The Daily Parker

Politics, Weather, Photography, and the Dog

Daylight saving time

I've never felt great about the Daylight Saving Time switch happening in the beginning of March, but here it is. Oddly, I have no trouble changing eleven or twelve time zones, but the one-hour change in the spring (but not the fall) always messes me up.

Anyway, if you live in the U.S. or Canada (excluding Arizona and Saskatchewan), it's probably an hour later than you think it is.

Time zone pet peeves

In general, people using words they don't understand, presumably to sound smart, drives me up a tree. In specific, I wish against reason that more people knew how time zones worked. Microsoft's Raymond Chen agrees:

One way of sounding official is to give the times during which the outage will take place is a very formal manner. "The servers will be unavailable on Saturday, March 17, 2012 from 1:00 AM to 9:00 AM Pacific Standard Time."

Did you notice something funny about that announcement?

On March 17, 2012, most of the United States will not be on Standard Time. They will be on Daylight Time. (The switchover takes place this weekend.)

Now, I'm one of the few people in the world who has implemented a complete time zone package for Windows systems, and regular readers will already know about my vocal defense of the Olson/IANA time zone database. So I don't expect most people to know the ins and outs of time zone abbreviations. But this is the point Chen makes, and I would like to make: if you don't know what you're writing, don't write it. Say "Central time" or "local Chicago time" instead of "Central Standard Time," if for no other reason than you'll be wrong about the latter 8 months out of the year.

Let there be light!

At this time of year, people from the tropics to the poles really become aware of changes in the lengths of the days. Yesterday Chicago had 11 hours of daylight for the first time since October 18th; we get 12 hours of daylight less than three weeks from now. Tuesday the sun set at 5:30pm for the first time since standard time returned on November 5th; it sets at 7pm on March 16th.

From the solstice through February 1st we only get about one additional hour of daylight (though, because of the Earth's orbit, most of it comes in the evening). But the really dramatic changes are now: from February 20th to April 20th, we get 3 more hours of daylight—an average of 3 minutes per day. Plus, the second weekend of March puts us into Daylight Saving Time, so sunsets occur more than two hours later in April than in February.

A direct result of lengthening days is increasing temperatures. It turns out that summer temperatures don't predict winter temperatures at all, but winter temperatures predict summer temperatures quite well. With only 12 days of snow on the ground this year, the warmest winter since the 1920s has felt more like Raleigh, N.C., than Chicago. This means, of course, next summer will feel like Raleigh as well. I can't wait.

Shooting the moon...again...

Sure, I've posted photos of the moon before, but it never gets old to me:

Well, all right, at 4½ billion years it is old to me, but you know what I meant.

On a side note, I just Googled "age of the moon" and discovered that many of the top results are from outside the reality-based community. For example, the second item on my results came from the Institute for Creation Research ("Biblical. Accurate. Certain."), in which one Thomas G. Barnes, D.Sc., begins with the assertion: "It takes but one proof of a young age for the moon or the earth to completely refute the doctrine of evolution." If you're a science teacher, you might want to have a look at this article, because it could be a great way to introduce kids to the meanings of theory, hypothesis, and fallacy.

And could someone please tell me what the credential "D.Sc." purports to be?

Shine a little light on me

The thing I like most about February: at the end of it, Chicago has an hour and a quarter more daylight than at the beginning of it. Today we have 10 hours of daylight, the most since November 10th, and on the 29th we have 11 hours and 14 minutes.

I notice this every year around now, just as I forget every year how grim December can be.

Quick updates

A couple of things have happened on two issues I mentioned earlier this week:

That is all for now. We in Chicago are bracing for 15 cm of snow tomorrow, so there may be Parker videos soon.

Oh, and: Kodak actually did file for bankruptcy protection today.

Just now, over Chicago

This looks a lot like a shot from last February:

It's still cool. And it's only about five minutes old.

It suggests, however, that I might want to rent a really cool lens sometime. I used the same equipment (Canon 7D, 200mm), but shot hand-held at ISO-400, f/5.6 at 1/1000, then developed it differently than the one from 11 months ago. I also shot this one raw instead of as JPEG, which gave me a lot more flexibility in post.

Mostly, though, we have clear skies and a full moon, so what more reason do I need?

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.