And yet people will say that 2000 is the beginning of the millenium, and 2020 is the beginning of a decade, because colloquially it's easier and understandable. And no amount of begging, pleading, or berating will change that (although it might get you punched in the face). That pope Gregory XIII neglected to include a year 0 in his calendar doesn't have to condemn us to suffer the mental gymnastics in our daily lives.

> 2020 is the beginning of a decade, because colloquially it's easier and understandable

But 2020 is technically the start of a decade, not just informally.

Well, technically every day is the start of a decade.

No that's what it informally means. Technically, decades start on the first day of a ...0 year, so not all days are the start of a decade.

What technique is this? I am unaware of any Office of Decades charged with deciding precisely what constitutes the sole definition of "decade".

> I am unaware of any Office of Decades charged with deciding precisely what constitutes the sole definition of "decade"

ISO 8601 defines what a 'decade' is.

I mean you're free to ignore it of course, like you're free to say March has 34 days if you want... but you may have trouble communicating with people and integrating with existing systems.

8601's definition of a decade is somewhat different from common parlance. They're using it only to mean "the first digit of a two-digit year", and doesn't really apply it beyond that. If you stick to only that definition of a decade, you're going to have communication problems with human beings.

Nah. 99/100 people will say the 90's decade is 1990-1999

A decade is just 10 years. There’s no specific start or end.

https://en.m.wikipedia.org/wiki/Decade

> A decade is a period of 10 years.

That's for informal use in speech, not what anyone building a formal system (the context of this thread) means.

That would imply that not all decades are 10 years long, sice there was no year 0.

Either that or it means that the first nine years were not part of any decade.

A decade is any interval of ten years, so all years are the start of a decade, except for the nine years at the end of the universe.

Which explains why it is so difficult to make a reservation at Milliways.

> so all years are the start of a decade

This isn't the standard technical meaning of 'decade'.

“Decade” isn’t a technical term, which is the point here. It has no intrinsic meaning except “a span of ten years”. Everything else is nominal, not technical; conflating the two is basically nerd sniping, and enlightens no-one.

> “Decade” isn’t a technical term

This whole article and thread is about building technical systems for dates.

In a technical context, 'decade' is a term with a specific standard meaning, which is that it starts on a year ending with a zero.

It's not nerd sniping to point that out in a thread already all about giving dates precise technical meanings!

The article is satire.

The thread is nothing but nerd sniping.

There is no technical context for time defining “decades” that is anything other than nominal.

The fact that people are so hung up on this detail is itself evidence that it has no concrete philosophical foundation. Any definition you care to toss around is arbitrary.

It is pure bikeshed, and this is what gives the article its glimmer of truth that validates the satire.

Says who? I routinely refer to something I did a long time ago as "two decades ago", whether the current year ends in zero, one, or something else.

> Says who?

ISO

I feel like this entire thread has been an elaborate attempt to demonstrate that you know an ISO definition. With the carefully constructed adjectives used to describe the definition ("standard technical meaning", "In a technical context") leading inexorably to the "ISO" gotcha.

To save others time, here's the ISO-8601 document which is apparently being referenced: https://dgn.isolutions.iso.org/obp/ui#iso:std:iso:8601:-1:ed...

"decade" is defined in 3.1.2.22:

decade time scale unit (3.1.1.7) of 10 calendar years (3.1.2.21), beginning with a year whose year number is divisible without remainder by ten Note 1 to entry: Decade is also used to refer to an arbitrary duration (3.1.1.8) of 10 years, however decade is not used as such in this document.

ISO 8601 is the standard technical way to refer to time and has been for ages - I guessed everyone who worked with computers and time would know about it sorry thought it was obvious.

What's not so standard, in my opinion, is that people be required to restrict their use of language to the noted restrictive sense of a definition as used "in [that] document."

Yes, yes, all of the adjectival disclaimers were used to try to align the discussion directly to how words are used "in [that] document." While the document is highly important, there are many technical contexts in which it is completely appropriate to talk about decades without the slightest consideration of how the same term might be used therein.

I don't think you read all of my comment. 2020 is absolutely the beginning of a decade. So is 2021. It's just not the same decade.

That is the real rub. It is like the word 'hacker'. No amount of 'but it really means' will change that. It is like the Mandela effect. People see and hear and remember what they want, but reality can be very different. But they will still go about their day with the 'wrong way'. Life will be just fine with something like this being 'wrong'.

When I do this rant, I like to note that "the 1800s" and "the 19th century", while very similar, are not the same 100 year interval.