Talk:ISO 8601

Wikipedia dates

Some people have proposed using ISO 8601 for Wikipedia dates. For more of this discussion, see Wikipedia talk:Manual of Style (dates and numbers).

It appears that it's rapidly becoming a de facto standard (if not yet de jure) at least for dates in Wikipedia citations.

Y10K

The Long Now foundation suggests that years should be written with five digits (ie 02003 for the year 2003) in order to avoid the Year 10,000 problem.

This is pointless: all it does is push the problem forward a few years to 100,000, and situation already exists for dates in the past (-10,000 and earlier.) May as well accept that the year number can have a varying number of digits -( 18:57 22 Jun 2003 (UTC)

• RFC2550: Y10K and beyond — RFC document published as an April Fools joke in 1999; still it contains many potentially useful ideas.

Without seeing that I assumed they were serious! Brianjd

I actually came to this article just to find the number of RFC 2550, which Google didn't find and which I'd misremembered as 2250. It's important to remember that Wikipedia is often useful as a different kind of search engine, rather than as a traditional encyclopedia. I think RFC 2550 should be referenced from the original article. Will Mengarini (talk) 21:20, 15 July 2017 (UTC) Will Mengarini (talk) 21:20, 15 July 2017 (UTC)

TIL that this client automatically signs my comments, doesn't stop me from doing so redundantly, doesn't stop me from doing so redundantly, and doesn't let me edit or delete them. Sigh. Will Mengarini (talk) 21:23, 15 July 2017 (UTC)

Micro seconds

It would be nice, when the article would say something about micro seconds. Is possible or is it not possible to store micro seconds in a ISO 8601 time stamp? Even if it is not possible, it is worth to be noted. --Ceving (talk) 15:37, 5 May 2017 (UTC)

Either the minutes field or the seconds field may include a decimal point (either a full stop or a comma) followed by as many digits as necessary. However, if the seconds are included, the minute can't have a decimal point or digits to the right of the decimal point. The data interchange partners must agree on the number of digits to the right of the decimal point. So if you're writing something for general use, and have no idea who is going to receive it, decimal points shouldn't be used. Jc3s5h (talk) 16:37, 5 May 2017 (UTC)

The previous answer is excessively cautious. A time expressed according to this norm as 00:00:00.000001 cannot possibly have another interpretation than one microsecond after midnight. So yes, microseconds can be unambiguously expressed. −Woodstone (talk) 12:05, 6 May 2017 (UTC)

I infer the intent of the standard is that if the parties exchanging information have not agreed to anything special, automated software can parse any valid string, without any hints, and without knowing the context. Some examples from the standard:

152746

52746+0100

15:27:46+01:00

985102T235030Z

985-102T23:50:30Z

My guess is someone figured out some situation where the interpretation could be ambiguous if the use of decimals, and the number of digits to the right of the decimal, was not agreed to in advance. If you sure the string is going to be read by a human, it's probably safe to use a decimal without advance permission. But if the string is to be parsed with software, it's safer to assume the author of the parser rigidly followed all the rules. Jc3s5h (talk) 12:18, 6 May 2017 (UTC)

Zulu time

User 108.161.123.51 removed the following text from the article:
UTC time is also known as Zulu time, since Zulu is the NATO phonetic alphabet word for Z.
with the following comment "GMT/UT are known as Zulu time not UTC".

The letter Z is a part of the ISO8601 standard and Zulu is a NATO phonetic for the letter Z. However it might be true that "Zulu time" means more than just "Zulu + time" and is more specific than a zero offset in any time system. I don't know if "Zulu time" is really limited to GMT/UT or not. Military time seems to be bound to UTC nowadays and "Zulu time" is still there so while it was GMT-only in the past it probably applies to UTC now. In any case I don't think choice of letter "Z" in ISO8601 is a coincidence, so it should be mentioned but probably with a different wording. If anyone has a reliable source to clarify what exactly "Zulu time" means and used to mean in the US military and other spheres please share it. Salmin (talk) 19:13, 12 June 2017 (UTC)

Zulu time is a military timescale used by some countries. It varies from UTC and from country to country. There's SO much bad information out there on the subject it's nearly impossible to find the truth. The truth is that Zulu and UTC both share the prime meridian as the starting point. From that people do the "Zulu time = GMT = UTC" inappropriately. The US military as an example does not use the standard time zone map so there are differences. If memory serves, Algeria or part of it, normally considered UTC+1, is Zulu time or UTC+0. There are many other small differences but the details are lost on most people. 108.161.123.51 (talk) 18:45, 14 August 2017 (UTC)

How to Pronounce 2017-07-28?

Does ISO 8601 specify how to pronounce a date such as 2017-07-28? We need a pronunciation that is consistent with the YEAR-MONTH-DAY order. --Roland (talk) 00:10, 29 July 2017 (UTC)

No, the standard makes no mention of pronunciation. Jc3s5h (talk) 00:15, 29 July 2017 (UTC)

Can we invent one, at least in English? --Roland (talk) 09:56, 5 August 2017 (UTC)

You can try whatever you want among your friends, and see if it catches on. But inventing pronunciations is not the purpose of Wikipedia; see WP:NOR. Jc3s5h (talk) 14:47, 5 August 2017 (UTC)

ISO 8601 cannot combine Weeks (W) and other designators?

In the aticle, under ISO 8601 durations it mentions:

Durations are represented by the format P[n]Y[n]M[n]DT[n]H[n]M[n]S or P[n]W as shown to the right.

I think should be: Durations are represented by the format P[n]Y[n]M[n]W[n]DT[n]H[n]M[n]S or P[n]W as shown to the right.

Tiny difference, but the point being that Weeks are allowed in the standard.

I could not find any mention of them NOT being allowed, and I would like to challenge you to come up with ANY good, valid reason to not allow them.

Granted, there are no examples that I could find that have weeks included. Amongst others, I looked here:

• in the W3C document there is no mention of something like "1Y2W" being disallowed.
• In the ISO standards document (page 9) it gives an example very similar to how it's written on Wikipedia, but also it is not said to be disallowed.

It seems like ISO 8601:2004 , has gotten rid of the example of W in durations altogether. So I'd also be fine with removing that W (and example) altogether.

And for your enjoyment: https://xkcd.com/1179/

ThatcherP (talk) 19:31, 15 August 2017 (UTC)