Talk:Daylight saving time

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	Daylight saving time is a former featured article. Please see the links under Article milestones below for its original nomination page (for older articles, check the nomination archive) and why it was removed.
	This article appeared on Wikipedia's Main Page as Today's featured article on July 11, 2007.
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At the top it mentions a few names for dst but in Wisconsin it is referred as daylight savings which is not included. Also more ways to mention dst could help improve this article. Quahog Eater (talk) 02:07, 4 March 2025 (UTC)Reply

At the top it says

Daylight saving time (DST), also referred to as daylight saving(s), daylight savings time, daylight time (United States and Canada), or summer time (United Kingdom, European Union, and others)

Are you saying that, in Wisconsin, it's called "daylight savings", without "time" at the end? If so, is that just a shortened version of "daylight savings time"?

And what "more ways to mention dst" do you know of that are used but aren't mentioned? Guy Harris (talk) 03:10, 4 March 2025 (UTC)Reply

Not much and maybe it is just a thing in Milwaukee county. It is called just "daylight savings" not "daylight savings time." It is interesting what it is called there but I'm not from there I just live in Wisconsin. Also I am not sure if it is just shortened. Quahog Eater (talk) 03:36, 28 August 2025 (UTC)Reply

That's what it's called in Australia (not DST or DT, specifically DS), and I wouldn't really consider it a shortened version of DST either. Well I mean, objectively it is lol, but culturally not..? Like, "daylight savings" is the complete term here, and you'd probs be looked at weird if you said "is it daylight savings time yet?". Adding the 'time' makes it sound idiomatic, like "is it go-time?" Or "it it party time?"
So I wanted to edit it to have "daylight savings" as a separate term for Australia.
Like:

Daylight saving time (DST), also referred to as daylight savings (Australia), daylight savings time, daylight time (United States and Canada), or summer time (United Kingdom, European Union, and others)

Or (for any Americans feeling insecure about their global status, as evidenced by below NIST discussion):

Daylight saving time (DST), also referred to as daylight savings time, daylight time (United States and Canada), daylight savings (Australia), or summer time (United Kingdom, European Union, and others) Shrampie (talk) 08:54, 20 June 2026 (UTC)Reply

The title figure is wrong. DST starts at 2am, and ends at 2am. See

https://www.nist.gov/pml/time-and-frequency-division/popular-links/daylight-saving-time-dst Betaneptune (talk) 14:20, 27 September 2025 (UTC)Reply

The last line in the caption: "Specific times of the clock change vary by jurisdiction". The diagram is not intended to illustrate the US rules specially, it just illustrates the one-hour jump and its direction. The world is a very big place, and the United States is just one part of it. Indefatigable (talk) 18:11, 27 September 2025 (UTC)Reply

But the US is the source of time for the world. NIST in particular. So it seems to me that the figure should be based on the US times, not the times of some random place, which it is now. Also, Wikipedia is based in the US. Maybe the figure should be omitted altogether. As is, the last line in the caption looks like the fine print that no one reads. Maybe add a couple of clocks for the UK method to illustrate that different regions change at different times. The UK changes from 1 to 2 for British Summer Time, and from 2 to 1 for Standard Time. Different from the US times!

"Through its own time scale, NIST provides time to the nation and the world via the internet and radio."

Quote is from https://www.nist.gov/time-frequency Retrieved 2025-09-27 Betaneptune (talk) 20:46, 27 September 2025 (UTC)Reply

All the quote from NIST means that they didn't block phone calls or internet connections from outside the US. There are a variety of national time laboratories that cooperate, through the International Earth Rotation and Reference Systems Service. Jc3s5h (talk) 21:07, 27 September 2025 (UTC)Reply

It clearly says that "NIST provides time to the nation and the world". Do you see the word "provides" there? Yes, there are atomic clocks -- weighted, mind you -- around the world. Something like 400, I believe. Now, we can't have 400 different independent sources of time! So NIST calculates them and comes up with a single time source. It says "NIST provides". That's more than not blocking phone calls and internet connections. In fact, what does that have to do with this anyway, especially phone calls? Betaneptune (talk) 21:16, 27 September 2025 (UTC)Reply

Do you see the word "provides" there? Yes, I see the word "provides", which does NOT necessarily mean "is the authoritative source of". The full paragraph from which that quote was extracted is

NIST, in coordination with the U.S. Naval Observatory, provides official time for the United States. NIST builds and operates the country’s most accurate atomic clocks, which help set the global time scale known as Coordinated Universal Time. Through its own time scale, NIST provides time to the nation and the world via the internet and radio. NIST develops chip-scale atomic clocks and calibrates clocks for customers such as stock exchanges. NIST researchers are working with international colleagues to redefine the second — the fundamental unit of time — using next-generation optical clocks.

That only uses "official" when referring to the US. It does not state that they provide official time to any other country, just that if you want to get UTC, you can get it from NIST. The National Physical Laboratory (NPL) in the UK, for example, also provides time services, and they say

NPL operates the national time scale UTC(NPL) and the UK primary frequency standards, and uses these to contribute to global timekeeping. We also disseminate accurate time and frequency to users across the UK, via services such as the MSF radio time signal, our internet time service, and NPLTime®. Atomic timekeeping underpins technologies that are part of our daily lives, such as mobile phones, the internet and global navigation satellite systems.

so they are the providers of official time in the UK. Users outside the UK can also use their time and frequency services - for example, I was able to use the SNTP command-line client on my machine to ping one of their NTP servers. A radio that can receive signals from their radio time signal, and that is located outside the UK, could also get time from them. as their page on that signal says ("The MSF radio signal is a dedicated standard-frequency and time broadcast that provides an accurate and reliable source of UK civil time. It is available 24 hours a day across the whole of the UK and beyond. ... The signal covers the whole of the UK, and can also be received throughout most of northern and western Europe.")

Yes, there are atomic clocks -- weighted, mind you -- around the world. Something like 400, I believe. Now, we can't have 400 different independent sources of time! So NIST calculates them and comes up with a single time source. You're talking there about International Atomic Time (TAI). That article says:

TAI is a weighted average of the time kept by over 450 atomic clocks in over 80 national laboratories worldwide.^[1] The majority of the clocks involved are caesium clocks; the International System of Units (SI) definition of the second is based on caesium. The clocks are compared using GPS signals and two-way satellite time and frequency transfer.^[2] Due to the signal averaging TAI is an order of magnitude more stable than its best constituent clock.

The participating institutions each broadcast, in real time, a frequency signal with timecodes, which is their estimate of TAI. Time codes are usually published in the form of UTC, which differs from TAI by a well-known integer number of seconds. These time scales are denoted in the form UTC(NPL) in the UTC form, where NPL here identifies the National Physical Laboratory, UK. The TAI form may be denoted TAI(NPL). The latter is not to be confused with TA(NPL), which denotes an independent atomic time scale, not synchronised to TAI or to anything else.

The clocks at different institutions are regularly compared against each other. The International Bureau of Weights and Measures (BIPM, France), combines these measurements to retrospectively calculate the weighted average that forms the most stable time scale possible.^[1] This combined time scale is published monthly in "Circular T",^[3] and is the canonical TAI. This time scale is expressed in the form of tables of differences UTC − UTC(k) (equal to TAI − TAI(k)) for each participating institution k. The same circular also gives tables of TAI − TA(k), for the various unsynchronised atomic time scales.

So, no, NIST does NOT "[calculate] them and [come] up with a single time source." That's done by the BIPM, who publish Circular T, containing tables of differences between their official UTC/TAI and the estimates of UTC/TAI provided by various laboratories, including but not limited to the NIST. What NIST provides is UTC(NIST), just as the NPL provides UTC(NPL). To convert those to UTC, the correction from the most recent Circular T for that particular source would be applied.

It says "NIST provides". That's more than not blocking phone calls and internet connections. Yes, it's providing unblocked radio, telephone, and Internet time services.

In fact, what does that have to do with this anyway, especially phone calls? Both NIST and NPL, and possibly other national time services, provide dial-up time services. The NIST's dial-up time service does not indicate that it is unavailable outside the US. The NPL's dial-up time service is not available outside the UK ("No, British Telecom’s premium rate telephone numbers, including that used by the NPL TTS, cannot be called from outside the UK.") Guy Harris (talk) 22:44, 27 September 2025 (UTC)Reply

You wrote, :That only uses "official" when referring to the US. It does not state that they provide official time to any other country,"

NIST wrote, "Through its own time scale, NIST provides time to the nation and the world via the internet and radio."

It says the nation AND THE 'WORLD'. Why should NIST provide unofficial time to the world? The article also doesn't specify which galaxy is being assumed. And all sorts of things. IOW, you're nitpicking and being, uh, overly pedantic.

Betaneptune (talk) 23:29, 27 September 2025 (UTC)Reply

Why should NIST provide unofficial time to the world? Because it'd be more effort to prevent anybody outside the US from communicating with their NTP server?

"Official" time, for a nation, is determined by the national government; the US government has designated the NIST as the provider of official time in the US - as their website says, "NIST, in coordination with the U.S. Naval Observatory, provides official time for the United States." The UK government has designated the NTP, not the NIST, as the provider of official time in the UK.

IOW You misspelled "IMO". Guy Harris (talk) 23:51, 27 September 2025 (UTC)Reply

International Earth Rotation and Reference Systems Service calculates a consensus time scale and a list of how much each national time scale is off from the consensus. National time laboratories steer their clock ensemble toward the consensus. To confirm this read a book such as McCarthy & Seidelmann, Time From Earth Rotation to Atomic Physics (Wiley-VCH, 2009). Jc3s5h (talk) 22:44, 27 September 2025 (UTC)Reply

Fine. Leave it as it is. Fine, keep your misleading figure. Yes, there's a complex web of places involved, but "provides" overrides all that.

"International Earth Rotation and Reference Systems Service" Yes, I saw that article. Seems to me, it had more to do with polar motion of the earth. Fine, keep your, uh, diagrams.

Wikipedia is an American invention, located in the US, using American English, AFAICT.

I had an even worse time with the "planetary system" and "2001" talk pages. I gave perfectly reasonable things to change and got shot down every time. I gave perfectly reasonable and correct points and got shot down every time. One person claimed I was a troll. In another case I was told "Original research", even though other things in the article were also original research. Apparently it's only "original research" when I mention it. I was talking about obvious things in the movie. You don't need some stupid reference for it! So be it. No more donations for you! I used to donate, but not anymore. Betaneptune (talk) 23:21, 27 September 2025 (UTC)Reply

but "provides" overrides all that. False, as explained repeatedly.

"International Earth Rotation and Reference Systems Service" Yes, I saw that article. Seems to me, it had more to do with polar motion of the earth. He may have mistakenly referred to the International Earth Rotation and Reference Systems Service, which deals with the "leap seconds" part of UTC, rather than the International Bureau of Weights and Measures (BIPM), which deals with the "Coordinated" part of UTC. The BIPM are the ones who do the work to coordinate all the individual atomic clocks to generate an averaged time value.

Wikipedia is an American invention Wikipedia was initially founded by some US citizens, and the Wikimedia Foundation is a US foundation headquartered in the US...

located in the US ...and its first server was in the US, with the application servers all currently in the US and several caching servers both inside and outside the US...

using American English ...but with the English-language Wikipedia supporting articles in American English and Australian English and British English and Canadian English and ... and Hiberno-English and ... and Indian English ... and New Zealand English ... and... (see the "See also" for the full set of templates for various English variants), so, no, it's not solely "using American English". (There are also non-English Wikipedias, but this article is in the English-language Wikipedia.)

But none of that makes the US primus inter pares in the English-language Wikipedia. Guy Harris (talk) 06:35, 28 September 2025 (UTC)Reply

I agree, but it might be nice to have an illustration that matches some large jurisdiction, rather than none at all. Jc3s5h (talk) 18:19, 27 September 2025 (UTC)Reply

the map of North America incorrectly features British Colombia as using daylight savings time. Gosensgo1992 (talk) 03:00, 7 March 2026 (UTC)Reply

BC has switched to DST ("summer time") every year since the 1950s. The map is not about being on "permanent" DST, but rather using it alternately each year with Pacific Standard Time (PST). Zefr (talk) 04:51, 7 March 2026 (UTC)Reply

yes but I was wondering about their upcoming permanent change Gosensgo1992 (talk) 04:59, 7 March 2026 (UTC)Reply

thank you for replying:) Gosensgo1992 (talk) 04:59, 7 March 2026 (UTC)Reply

OK, so what the announcement from the government of British Columbia says is:

B.C. will adopt permanent, year-round daylight saving time after clocks shift forward an hour on Sunday, March 8, 2026

Per that, as of the switch to DST on 2026-03-08, BC is now on DST and will continue to be on DST even after some other North American locations turn their clocks backward again in November.

The map, however, currently claims that BC is not on DST, rather than claiming that it's on permanent DST (as in "the offset is permanently UTC-7", as in to Mountain Time without DST, rather than "the UTC is permanently UTC-8", as in Pacific Time without DST). It should be fixed, which would involve adding an additional "permanent DST" color. Guy Harris (talk) 21:16, 3 April 2026 (UTC)Reply

ahhhh thank you! Gosensgo1992 (talk) 21:50, 3 April 2026 (UTC)Reply

For the comment to which you're responding, you're welcome. For the change to the map, however, that wasn't me, it was a couple of other editors. Guy Harris (talk) 23:06, 3 April 2026 (UTC)Reply

The redirect Y2K7 problem has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 March 9 § Y2K7 until a consensus is reached. Mathguy2718 (talk) 03:07, 9 March 2026 (UTC)Reply

THIS edit got removed after all of 3 minutes.

The reason given for removal was "original research". But what is being presented is simple straightforward fact:
If there were no clocks, you would wake up with the sunrise. And what Daylight Savings Time accomplishes is a shift toward this more natural rhythm. It doesn't get any simpler than this. Those who debate this issue fail to understand this most fundamental purpose. The purpose of an encyclopedia is to present useful information. And millions of people do not have this base level understanding on this topic.

What is being presented here is the understanding that was known by Benjamin Franklin. Along with those who followed and promoted this time shift adjustment. Here is a direct quote regarding the paper written by George Hudson who is understood to be the first person to formally propose this daylight savings time shift:

"Mr. Maskell said the mere calling the hours different would not make any difference in time. It was out of the question to think of altering a system that had been in use for thousands of years, and found by experience to be best.^[1]

Here he is explaining how natural time long before clocks existed had people waking up with the sunrise. And that clocks do nothing to alter the natural rhythm. This reference will be the basis for inclusion of this most fundamental understanding back into this article. Ideally, a policy decision will be an informed decision. And it is the duty of Wikipedia to present this info. --Concord19 (talk) 18:31, 16 July 2026 (UTC) Concord19 (talk) 18:31, 16 July 2026 (UTC)Reply

Your edit was reverted because it cited no sources. If you want to add it to the article, I hope you come up with better sources than a statement from 1895. Schazjmd (talk) 18:34, 16 July 2026 (UTC)Reply

Quotes from the 1800s are actually excellent references. It shows how long this basic info has long been understood. Here is a direct quote from the words of George Hudson himself:

It cannot be too strongly borne in mind that the time standard in ordinary use... is merely an abstraction devised for human convenience, and does not represent any actual time interval existing in nature. ...the time in ordinary use is only an abstraction, so to speak, specially arranged to suit human requirements, and does not by any means agree with the time as indicated by the sun. ...our time is merely an artificial standard, which might be further adjusted if by so doing it could be made more subservient to our requirements.^[2]

Hudson goes into detail explaining how the equation of time specifies the difference between "natural time" (as determined by the sun, as read on a sundial) versus time as read on a mechanical clock. And his argument is that we are at liberty to make adjustments away from mechanical time so that clocks will more closely match natural time. He calls his adjusted time "seasonal time", explaining how it brings clocks better in line with the equation of time (natural time). And this is essentially the phenomenon that is being displayed in the image. --Concord19 (talk) 19:11, 16 July 2026 (UTC)Reply

DST has only been a concept since relatively recently in History,widely adopted in Europe and North America and first used in 1908 in Thunder Bay, Ontario, Canada, as per https://www.timeanddate.com/time/dst/history.html, it is in no way synchronized to the natural sleep cycle as countries have been reverting to either Year-Round Standard Time, or year-round Daylight Savings Time as per https://www.ucanwest.ca/blog/media-communication/the-history-of-daylight-saving-time and https://en.wikipedia.org/wiki/Daylight_saving_time. DST was also a wartime measure according to https://www.transportation.gov/regulations/time-act and https://www.war.gov/News/Feature-Stories/story/Article/1779177/daylight-saving-time-once-known-as-war-time/ Enjoy readint more about it. ~2026-41261-06 (talk) 11:16, 24 July 2026 (UTC)Reply