Every year, millions of people endure the biannual stupidity of Daylight Saving Time (DST), and we have a handful of historical geniuses to thank for this life-ruining ritual. Sure, they thought they were solving big problems, but instead, they handed future generations a headache disguised as innovation. Benjamin Franklin joked about saving candles by waking up earlier, and people were dumb enough to run with it. Yes, folks, this is why satire needs a disclaimer: Franklin was trolling, but the world took him seriously. And here we are, centuries later, living his joke as reality.

The Prime Meridian is the universally decided zero longitude, an imaginary north/south line which bisects the world into two and begins the universal day. The line starts at the north pole, passes across the Royal Observatory in Greenwich, England, and ends at the south pole. Its existence is purely abstract, but it is a globally-unifying line that makes the measurement of time (clocks) and space (maps) consistent across our planet.

The Greenwich line was established in 1884 at the International Meridian Conference, held in Washington DC. That conference's main resolutions were: there was to be a single meridian; it was to cross at Greenwich; there was to be a universal day, and that day would start at mean midnight at the initial meridian. From that moment, the space and time on our globe have been universally coordinated.

Having a single prime meridian brings to the world's cartographers a universal map language allowing them to join their maps together, facilitating international trade and maritime navigation. At the same time, the world now had one matching chronology, a reference by which today you can tell what time of day it is anywhere in the world simply by knowing its longitude.

For decades, the Moon’s subtle gravitational pull has posed a vexing challenge — atomic clocks on its surface would tick faster than those on Earth by about 56 microseconds per day. This extremely small difference doesn’t seem like much, but it could disrupt the precise timing needed for important activities like spacecraft landings and communicating with Earth.

Now, researchers at the National Institute of Standards and Technology (NIST) have developed a plan for precise timekeeping on the Moon, paving the way for a GPS-like navigation system for lunar exploration. The research, published in The Astronomical Journal, focuses on defining a theoretical framework and mathematical models necessary for creating a lunar coordinate time system.

This innovation is crucial for NASA’s ambitious Artemis program, which aims to establish a sustained human presence on the Moon and may be an important steppingstone for exploration of the cosmos.

The picture shows my home-built digital clock, using Nixie tubes for readout. In contrast to most other nixie clocks being built these days, this clock does not use any transistor or IC for controlling and driving the tubes. Instead, the driving logic is built from trigger tubes, together with resistors, capacitors and silicon diodes. A video is on youtube.

This project is a followup to a similar clock I built between 2002 and 2007, documented on its own page. That clock used regular NE-2 style neon lamps as logic elements. Unfortunately, after a while, as these lamps aged, the clock became unreliable and unusable.

The new clock uses trigger tubes, of the МТХ-90 type (that's in Cyrillic characters; transliterated to Latin script it's MTH-90), which are widely available as "new old stock" on Ebay. Trigger tubes are essentially regular neon lamps with an extra "trigger" electrode, which can be used to ignite them. However, in this circuit I don't use the trigger electrode.

The above shows my home-built digital clock. It uses Nixie-tubes for readout. In contrast to most other nixie-clocks being built these days, my clock does not use any transistor or IC for driving the tubes. Instead, the driving logic is built from neon lamps, together with resistors, capacitors and silicon diodes.

The project started in 2002, when our university library was selling old outdated or otherwise superfluous books, and I very cheaply bought the book "Electronic Counting Circuits" by J.B. Dance, published in 1967, and apparently only ever lent three times by our library, all in 1973. It described how neon lamps can be used as logic elements in a ring counter, exploiting the fact that they need a higher voltage to ignite (the striking voltage) than to stay lit (the maintaining voltage):

The Hafele–Keating experiment was a test of the theory of relativity. In 1971,[1] Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four caesium-beam atomic clocks aboard commercial airliners. They flew twice around the world, first eastward, then westward, and compared the clocks in motion to stationary clocks at the United States Naval Observatory. When reunited, the three sets of clocks were found to disagree with one another, and their differences were consistent with the predictions of special and general relativity. //

Hafele, an assistant professor of physics at Washington University in St. Louis, was preparing notes for a physics lecture when he did a back-of-the-envelope calculation showing that an atomic clock aboard a commercial airliner should have sufficient precision to detect the predicted relativistic effects.[11] He spent a year in fruitless attempts to get funding for such an experiment, until he was approached after a talk on the topic by Keating, an astronomer at the United States Naval Observatory who worked with atomic clocks.[11]

Hafele and Keating obtained $8000 in funding from the Office of Naval Research[12] for one of the most inexpensive tests ever conducted of general relativity. Of this amount, $7600 was spent on the eight round-the-world plane tickets,[13] including two seats on each flight for "Mr. Clock." They flew eastward around the world, ran the clocks side by side for a week, and then flew westward. The crew of each flight helped by supplying the navigational data needed for the comparison with theory. In addition to the scientific papers published in Science,[5][6] there were several accounts published in the popular press and other publications. //

Presently both gravitational and velocity effects are routinely incorporated, for example, into the calculations used for the Global Positioning System.

Our beloved NTP protocol appears to work in a deep space environment (as tested in a simulation with a 4 hour RTT):

https://deepspaceip.github.io/testbed/ntp.pdf

PTP daemon (PTPd) is an implementation the Precision Time Protocol (PTP) version 2 as defined by 'IEEE Std 1588-2008'. PTP provides precise time coordination of Ethernet LAN connected computers. It was designed primarily for instrumentation and control systems.

No, you do not need to set all Livewire devices to be a PTP clock slave. Some devices that aren't fully AES67 compliant can only accept Livewire clock.

What's important is any clocks are all synced together, somehow, so they both have the same reference.

Can we use research and policy to change (or not change) the clocks for the last time? //

In 2022, Gentry and an interdisciplinary team of colleagues added to that body of research, publishing a study in the journal Time & Society that showed the rate of fatal motor-vehicle accidents was highest for people living in the far west of a time zone, where the sun rises and sets at least an hour later than on the eastern side. Chronobiology research shows that longer evening light can keep people up later and that, as Gentry found, morning darkness can make it harder to get going for work or school. Western-edge folks may suffer more deadly car wrecks, the team theorized, because they are commuting in the dark while sleep deprived and not fully alert.

With all the hullabaloo over the health and safety of setting clocks forward an hour in the spring for Daylight Saving Time (DST) and back in the fall with Standard Time (ST), could where you live in a time zone actually have a more profound effect? I asked Gentry. “That’s very possible,” he said.

Time researchers make this point, and research results and public opinion polls reflect it: Something is awry about the way we mark time. //

Permanent DST meant that the sun also rose and set later in the winter. Results published in 2017 associated year-round DST with a greater likelihood of feeling down in the winter as well as sleeping later on weekends, a phenomenon known as social jet lag. Chronobiologist Till Roenneberg and colleagues coined the term nearly two decades ago to describe the chronic sleep deprivation that people experience when they have to get up for school or work before they would awaken naturally. //

“We all agree as researchers that the safer option is to go for perennial Standard Time,” said Blume, a postdoctoral researcher at the University of Basel in Switzerland.

The nonprofit organization Save Standard Time lists endorsements from more than 30 sleep-science and medical organizations—including the American Academy of Sleep Medicine, the American Medical Association, and the American Academy of Neurology among others—in addition to individual scientists and researchers.

Here, I feel compelled to note that the last time we tried permanent DST, it didn’t go well. In attempt to conserve energy, Congress established a trial period of year-round DST in late 1973. But public approval dropped precipitously as Americans faced the reality of dark winter mornings. By October 1974, the country had reverted to four months of yearly ST. //

Things gets interesting on either side of a time-zone boundary, where the sun position is essentially the same, but the clock time is different. In late January, for example, the sun sets around 6:10 pm in Columbus, Georgia in Eastern Time, but at 5:10 pm just over the time-zone border in Auburn, Alabama.

People living on the late-sunset side of a time-zone border, like those in Columbus, tend to go to bed later, sleeping an average of around 20 minutes less each night than those on the early-sunset side, like those in Auburn, according to a 2019 study published in the Journal of Health Economics. Drawing on large national surveys and data from the Centers for Disease Control and Prevention, researchers found that health outcomes associated with sleep deficiency and social jet lag were worse for the late-sunset folks. Their wages were also about 3 percent lower than those of early-sunset people, who, better rested, were presumably more productive. //

Another tricky aspect of time zones is that they don’t strictly adhere to longitude lines but instead meander to accommodate city and state boundaries. In the US, all the time zones except Pacific Time encompass areas west of what would be the natural time-zone boundary. Communication professor Jeffery Gentry and a team that included Eastern New Mexico University professors with expertise in geography, biology, and education have dubbed those regions west of the geographic time zone “eccentric time localities,” or ETLs.

In these ETLs, sunrise and sunset time may occur more than an hour later than the eastern side of the time zone. For example, geographically, Marquette, Michigan, should be in Central Time, but instead, the city lies in an ETL in Eastern Time. In late October, the sun rises at around 7:10 a.m. Eastern Time in Bangor, Maine, but not until around 8:30 am in Marquette. //

Gentry would like to see time zones redrawn. But other policy fixes could help as well. //

A body of research shows that even dim light can suppress melatonin production and delay sleep. Blue light from fluorescent lights and our ubiquitous screens, which has the shortest wavelength and highest energy of light that the human eye can see, has a particularly powerful effect on circadian rhythms. //

And, although it sounds like a radical idea, states could also adjust time-zone boundaries. “I don’t think we want 10 time zones, but maybe we add one for the Northeast,” said Malow. Because the New England states are so far east, winter sunsets come early—before 4 pm in December in parts of Maine. //

nimelennar Ars Praefectus
6y
8,590
Subscriptor
Dzov said:
lol. Make sunup and sundown always 8am and 8pm respectively and your work day lengthens and shortens throughout the year and based on your latitude.
You can work at the North or South Pole. You punch in at 8 a.m., and punch out at 8 p.m., six months later.

The outage highlights how extensive people's reliance on technology has become and how an error based on something as trivial as a calendar date can upturn entire businesses and disrupt people's day. While some gas stations were still able to accept other forms of payments, those that relied on the broken terminals found themselves missing out on business. RNZ reported speaking to someone who was declined service by four gas stations due to the outage. //

Z1ggy Ars Legatus Legionis
14y
15,264
fahirsch said:
Well, it's just a one day problem that won't repeat until 2028😃
So if i know how bugs get fixed, it wont get fixed until 2/29/2028.

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

It’s not NTP. There’s no way it’s NTP. It was NTP

Also known as the Y2K38 Bug, The Unix Y2K Bug or Epochalypse

The year 2038 problem is a problem caused by how some software systems store dates. When these dates reach 1 second after 03:14:07 UTC on 19 January 2038 they could have an error or incorrectly store the wrong date (in some cases 20:45:52 on Friday, 13 December 1901).

This server also provides secure Roughtime service. It is monitored and maintained at the same service level as the NTP service provided. The time is synchronized with stratum 1 upstreams.

The introduction of railroads changed a lot, including time; with every town having its own time, marked at the sun's zenith, scheduling was a mess. //

Charles F. Dowd tamed time.

The career educator conceived a plan so audacious it’s hard to believe there was an era when his vision for the world didn’t exist.

Dowd created time zones. He put the rotation of the Earth, the rise of the sun, the movement of the heavens and the genesis of eternity itself on an artificial schedule for the benefit of mankind.

"To regulate the time of this Empire Republic of the World is an undertaking of magnificent proportions," the Indianapolis Sentinel wrote on Nov. 21, 1883, three days after railroads instituted time zones across North America. //

We recalcitrant Americans came late to the party, not legally adopting the time zone system until 1918, during the Great War, but the railroads bought into the new system in 1883, as it made schedule-keeping a lot easier. //

In one of history's little ironies, Charles Dowd was killed in 1904 when he stepped in front of a train; history has not recorded whether or not that train was running on time.

Already endangered, the leap second might have a practical successor soon. //

One of the leading thinkers on how humans track time has a big, if simple, proposal for dealing with leap seconds: Don't worry about them. Do leap minutes instead, maybe one every half-century or so.

"We all need to relax a little bit," said Judah Levine, leader of the Network Synchronization Project in the Time and Frequency Division at the National Institute of Standards and Technology (NIST), to The New York Times. Leap seconds—when coordinated, near-impeccable atomic time is halted for one second to synchronize with the Earth's comparatively erratic movements—are a big headache, especially to computer technology.

The International Bureau of Weights and Measures (IBWM) has already voted to eliminate leap seconds entirely by 2035, or at least how they are currently implemented. Levine plans to submit a paper outlining a "leap minute," timed to the next World Radiocommunications Conference held by the International Telecommunication Union (ITU).