Notes from Florida

Russia Ends Daylight Saving Time

Sun, 6 Mar 2011 13:16:04 -0500

Russia abolishes DST. After this summer, daylight saving time will no longer be used in Russia.

Antiquated, Frustrating...

Sun, 6 Mar 2011 12:57:22 -0500

A message from our homeowner's association included the following gem:

...March 13th is the return to Daylight Savings Time. This means students and those that hit the roads early in the morning will once again find themselves sharing the road in the dark. Please exercise extra caution and help make the change to this very antiquated, frustrating and personally very irritating seasonal change a safe one.

Latest Sunrise Since 1975

Wed, 3 Nov 2010 07:00:53 -0400

This article from KSBY in California correctly points out that this week we will see the latest sunrises since the failed year-round nationwide DST experiment of the 1970s.

In the case of Orlando, Florida, the latest sunrise will occur November 6th, 2010 when the sun will not rise until 7:41 EDT. This is thanks to the federal extended daylight savings law which took effect in 2007. Because the end of DST is tied to a weekend instead of a calendar date, we are just now seeing the worst case.

Beware The Dawn

Tue, 2 Nov 2010 20:20:49 -0400

Not an early riser? You might like this quote from E. R. Eddison's novel The Worm Ouroboros (warning: Archaic Language):

Truly I was seldom so uncivil as surprise Madam Aurora in her nightgown. And the thrice or four times I have been forced thereto, taught me it is an hour of crude airs and mists which breed cold dark humors in the body, an hour when the torch of life burns weakest.

iPhone DST Bug Hits UK

Mon, 1 Nov 2010 22:05:34 -0400

Daylight saving time strikes again. It seems like DST has caused more errors than Y2K ever did. The latest is a bug that caused iPhone alarms to be off by one hour when the time changed in the UK. Same thing happened earlier in Australia.

DST means designers of gadgets that use time can never simply subtract two times to find the difference, or add a duration to a time to find a new time, but must wonder whether the clock has taken a flying leap forward or backwards in the interim.
Confusion is inevitable.

What Time is Noon?

Mon, 26 Apr 2010 20:39:35 -0400

Once again we turn to the helpful folks at the US Naval Observatory for some interesting facts relating to time, time zones, and daylight saving time. Today, we're looking at transit times for the sun for Orlando, Florida for the year 2010. The term transit refers to the time at which an astronomical object, in this case, the sun, was nearest the zenith. For the northern hemisphere, that means the time at which the object (the sun) was located due south.

This is interesting, because for all of history, up until the invention of time zones in the 1800s, the transit of the sun was how towns and cities kept time. The transit of the sun was, by definition, local noon.

Obviously, the sun doesn't transit everywhere at the same moment. Within a one-hour timezone, local noon will occur an hour earlier at the eastern edge of the timezone than it does at the western edge. Properly designed timezones will ensure that no location in the timezone has to set their clocks more than 30 minutes different from local solar time.

A town which sets its clocks to noon at the transit of the sun has the best possible agreement between solar time and clock time. Any other system of setting the clock, such as standard time, or daylight saving time may be measured against this standard.

The astronomical tables from USNO must be used, because the time of transit is not fixed, but varies throughout the year by about plus or minus 15 minutes, according to the equation of time.

The questions before us are: How good is the agreement between clock time and solar time in Orlando, Florida using standard time, and how good is it using daylight saving time? Since Orlando is near the center of the state, it represents a good average for other cities in Florida.

For example, on March 1st, 2010, local solar noon occurred in Orlando at 12:38 PM, EST. On that day, our clocks were 38 minutes fast relative to solar time. On March 14th, 2010, the first day of daylight saving time, local noon was at 1:35 PM and our clocks were 95 minutes fast relative to solar time.

Using the page at:

http://www.usno.navy.mil/USNO/astronomical-applications/data-services/mrst-us

we obtained this information for all 365 days of 2010, and did some calculations. Wow.

Even before considering daylight saving time, Orlando's clocks are an average of 25 minutes fast. That's an average for all year assuming no daylight saving time. Orlando's clocks are ahead of solar time, every day all year. There is never a day when they are correct or behind, whether you consider daylight saving time or not.

When you do consider daylight saving time, the clocks are more than 30 minutes fast for 307 out of the 365 days, including the entire 238-day period of DST. The average error for the duration of DST is one hour and 24 minutes fast.

How many days are there when daylight saving time gives us better agreement with local solar time? None. Zero. Never happens.

However, there are 120 days during the year where Orlando's clocks would actually be in better agreement with solar time if they were set back an hour, instead of ahead by an hour. Maybe we should call it darkness saving time.

Bangladesh Cancels DST

Mon, 22 Mar 2010 20:13:47 -0400

The cabinet of Bangladesh permanently cancelled daylight saving time this year. In an editorial, The Daily Star of Bangladesh suggests that the main problem was that DST was continued too late into the fall. This is indeed a good point, and the ill will this created is cited as the reason for the cancellation.

However, they failed to notice that Bangladesh is also closer to the equator than many locations where DST is more successful. Bangladesh is around 37 degrees N. Latitude, which is similar to Raleigh, NC.

That's well north of Florida, but far south of London (51 N), where daylight saving time was invented.

Dreaded Day Arrives

Mon, 15 Mar 2010 08:56:00 -0400

It's a good news/bad news situation. The bad news is another 230-some days of DST. The good news is another dose of publicity for the effort to eliminate it.

Welcome to those who found the site through Facebook. You can help the cause by mentioning this site using your favorite social networking tools. Thanks! We could use links.

One of the reasons daylight saving time is difficult to get rid of is that it has happy associations for people. Because it happens in the spring, people associate it with pleasant weather, longer days, etc. Many people are too young to remember it any other way, but I assure you that spring days were just as pleasant without DST. I have seen news stories that imply that DST makes the days longer.

Just for the record, DST does not cause the baseball season to get underway, it does not cause March Madness, or pleasant spring days, nor lengthen the days, make the birds sing or affect anything except humans and our clocks. DST is also not the only way to remind people to change their smoke detector batteries.

Unfortunately, people associate the return of standard time with the onset of winter.

Well, folks, the seasons happened in pretty much the same way without DST!

The only way to correct public misperceptions is through education.

Chilean EarthQuake Shortens Day, NASA Says

Tue, 2 Mar 2010 20:27:25 -0500

Scientists at NASA say the the earthquake in Chile may have shortened our days by about 1.26 microseconds. This may not seem like much, but it is a bigger change to the length of the day than any legislation ever passed.

Just a reminder: Daylight Saving Time legislation does not change the length of the day, or cause pleasant spring weather. These things were happening eons before DST was conceived.

Recent DST News Items

Sun, 28 Feb 2010 20:17:50 -0500

Time is time at Standard.net
Anti-DST revolution at Indiana Daily Student

Also, many countries around the world are dealing with the difficulties of Daylight Saving time. It seems like they have adopted it as a sort of cargo cult thing. All the advanced western countries are doing it, therefore we should too. Countries like Fiji, Pakistan, and India all are struggling with DST. Pakistan is having trouble keeping the electricity on, but has boldly added the confusion of DST into the mix.

DST is completely useless in locations close to the equator.

In Fiji, they change the time school starts while DST is in effect so that students and teachers don't have to get up in the dark. Do they realize how silly it is to change the clocks on the one hand, and then on the other hand behave like they hadn't changed them?

One Time Must Be Standard Time

Sat, 20 Feb 2010 08:21:30 -0500

Well, the effort to end DST in Utah has failed, because... I am not making this up, a 13 year-old boy explained to legislators that ending daylight saving time would mess with the tilt of the earth, and affect Utah's relationship to the equator.

We should at least be able to educate school children better than that. Legislators are admittedly more difficult.

The Utah bill required a single time all year, but left the option of whether it should be daylight time, or standard time.

The option of year-round daylight time might not be that horrible, just because after a few years of that, people would simply adjust the starting times of schools and businesses, and we would have standard time in all but name.

However, the year-round-daylight-time option is off the table, especially in Florida. For one thing, federal law specifically allows a state to use year-round standard time. If the state legislature passes it, it's a done deal. There is no such provision allowing year-round daylight time. So that means there would have to be changes at the national level to permit it. A change to year-round daylight time literally makes a federal case out of it.

The second reason is that it has been tried before. Back in the 1970s energy crisis, the Nixon administration tried year-round nation-wide daylight saving time. This was abandoned after one year under intense protest and criticism. If you don't remember, several school children were killed in traffic accidents in the dark before school, right here in Florida. This was national headline news. It seemed like every week or so, there was another death. There is no way any politician is going to vote for something associated in the public mind with killing school kids.

Utah Bill Could End DST

Sat, 6 Feb 2010 09:40:28 -0500

This article in the Salt Lake City Deseret News announces introduction of a bill that would end the springing forward and falling back in Utah.

Interestingly the bill doesn't say whether Utah should have standard time all the time or daylight saving time all the time, just that there should be one time all year. That detail is left for a later vote.

By What Authority?

Sat, 9 Jan 2010 11:27:12 -0500

By what authority do we use the Gregorian calendar in the United States? We have numerous laws in the United States affecting the time and calendar. We have laws defining holidays, time zones and clocks, but nowhere that I can find has the US ever said legally and formally that the Gregorian calendar is our calendar.

When the United States declared independence from Britain, Britain and its colonies had already adopted the Gregorian calendar. The founding fathers had more important things to do than fiddle with the calendar. The constitution mentions several specific years and dates, but doesn't specify how those dates are to be determined.

I find it remarkable that we have been using something as important as the calendar for hundreds of years simply by social convention. Even in the 21st century, many of our computers and other high tech devices use the same method of determining the calendar date prescribed by Pope Gregory XIII in 1582.

In writing computer software it is good practice to cite the requirements that a module is meeting. While working on software that did calendar calculations, I wanted to cite the governing requirement for why it was calculating the date in a certain way. There didn't seem to be an ANSI standard, or an internet RFC, or a military standard, or even an act of congress. I eventually cited the papal bull Inter Gravissimas, Pope Gregory XIII, 1582. (Which gives the algorithm for determining the date, and gives examples through the year 2000.)

I have no objection to this state of affairs. It shows how well we can get along without legislation being necessary. If congress got involved it could only screw things up.

DST and Your Atomic Clock

Fri, 1 Jan 2010 13:21:40 -0500

Even though a clock synchronizes with the atomic clock time signal broadcast by WWV, it may still have the wrong time. I have one and it always keeps excellent time, except when it's off by an hour.

This article from the Oregon Mail Tribune does a good job of explaining why.

Some clocks incorrectly assume that DST starts and ends on a specific date, instead of obeying the DST signal from WWV. Since congress changed the rules, that assumption is invalid. Apparently, there is no way to tell when you buy a clock whether it does the DST adjustment properly or not.

DST: The Movie

Sun, 13 Dec 2009 16:36:13 -0500

Enjoy some humor from the tech-oriented web comic XKCD.

http://www.xkcd.com/673/

Hover mouse over comic for additional humor.