Tell HN: Today is the 21st day of the 21st year of the 21st century | Hacker News Reader

Tell HN: Today is the 21st day of the 21st year of the 21st century

49 pointssc9024 comments

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This is all ultimately arbitrary

Yes but it's fun.

I haven't had this much fun since September 9th, 1999...

Almost. it’s the 21st day of the 22nd year... 2000 was year 1.

Trolling, are you?

Apparently, pointing out facts is now trolling..

No, there was a pretty big discussion about 0 and 1 index ranges on HN yesterday.

https://news.ycombinator.com/item?id=25833557

The year the new century started on was part of the discussion. People are still debating as to whether the century started in 2000 or 2001.

Sorry, I should have been more clear. In 2000 there was a big debate over whether that was the first year of the new century. I sincerely thought that it had been settled long ago. Year 0 never existed (Christ is conventionally born on year 1 [1]), and the first hundred years (first century) go from 1 to 100. The second hundred years (second century) begin in 101, and so on.

[1] https://en.m.wikipedia.org/wiki/Year_zero

Another way to put it is that we don't number calendar years the way we do birthdays/ages.¹ Which probably accounts for some of the popular confusion here.

Your 23rd birthday is at the end of your 23rd year, and you're "23" from then until the 24th birthday. But you're actually progressing through your 24th year at that point.

Conversely, during the year called "2000" we were in the 2000th year. We completed 2000 years at the end of it. Upon which we started marking progress in the 2001st year.

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¹Gregorian calendar/Western-style birthdays

This is a good distinction. The Japanese tradition might serve as an example of different aging paradigms (also present in other areas of the world). https://en.wikipedia.org/wiki/East_Asian_age_reckoning

This makes sense. That being said, convention is very useful until it is broken for further optimization and setting better standards. I'm just not sure that a debate over "when it really started" is useful in that specific applications can define the start and end based upon what is needed rather than what is right, wrong, or accepted by convention. One exception to this is that non-specialists or students may learn something from the debate (provided it is public). A more useful debate would be whether or not we should rid ourselves of daylight savings time!

There was no year 0. A century is 100 years. So the first century was years 1 - 100, and the 20th from 1901 - 2000.

I regret to inform you that in the Gregorian tradition you are incorrect. If you are referring to some other tradition, please provide further explanation.

Please review: https://www.timeanddate.com/counters/mil2000.html

I thought HN likes zero based indices? 2000 would be the zeroth year.

One definition of "first" is "preceding all others" [0], so something with an index of 0 would still be the first item.

Apparently the definition of "zeroth" is "being numbered 0 in a series" [1], so something with an index of 0 could be both the "first" and the "zeroth" item...

However, another definition of "first" is "one that is number one in a series", so the headline of this post is both accurate and inaccurate, depending on which definition you want to use, I suppose.

0: https://www.merriam-webster.com/dictionary/first

1: https://www.merriam-webster.com/dictionary/zeroth

Yea it's mostly a joke and shows how a lot of this is contextual. I personally consider 1999-2000 the transition into the 21st century. Arguments otherwise are little more than awkward pedantry. Year 2021 could be seen as either the 21 or 22 year of the 21st century but i'm willing to side with the validity of OP's title.

Is it? The first century spanned year 1 to 100 (there was no year zero). So the XX00 year is considered to be part of the preceding century. Thus 2021 is indeed the 21st year of the 21st century.

If 2000 is part of the previous century, was 2001 actually the true start of the new millennium?

That's the standard practice, I believe. Presumably that's why Arthur C Clarke chose the year 2001 for the name of his book rather than 2000.

Today 9 PM will be 21st hour of the 21st day of the 21st year of the 21st century.

You could say the same thing in every month of this year.

No; this is the 21st day of the year, not the 21st day of some month in the year.

I hope you wrote it at 21:21:21 ;)

But 00:00 to 01:00 is the first hour.. so 21:00 to 22:00 is the 22nd hour, etc.

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