LWN's 2020 vision

Posted Jan 1, 2020 22:45 UTC (Wed) by excors (subscriber, #95769)
In reply to: LWN's 2020 vision by halla
Parent article: LWN's 2020 vision

Your argument is valid when talking about the 21st century or the 3rd millennium. If those started in 2000, the 1st century would have to be 99 years long to make it add up (in which case it wouldn't be a century so the 21st century would actually be the 20th). But decades are counted differently - nobody ever talks about the 203rd decade, so there's nothing contradictory about the convention where decades start in years divisible by 10.

LWN's 2020 vision

Posted Jan 2, 2020 3:17 UTC (Thu) by areilly (subscriber, #87829) [Link] (2 responses)

The first century was an invention of the sixth century, so it doesn't really matter how many years it had, and arguments to logic generally get confused about the non-existence of 0AD (1BC leads straight to 1AD in Anno Domini reckoning). No one was counting years that way, at that time.
So there isn't even anything contradictory about starting the 21st century in the year 2000, as most of the world actually celebrated. Of course having an excuse for another big party a year later is also fine.

LWN's 2020 vision

Posted Jan 9, 2020 1:10 UTC (Thu) by gwg (guest, #20811) [Link] (1 responses)

> So there isn't even anything contradictory about starting the 21st century in the year 2000, as most of the world actually celebrated. Of course having an excuse for another big party a year later is also fine.

On January 2nd, how many days of January have passed ?
(Hint: It's not 2.)

i.e. the name of the time period is the amount of time that will have passed when that period has ended.
On January 2nd, you are part way into the 2nd day, and 1 and a bit days have passed.
2 days will have elapsed at the start of January 3.

This is why we are in the 21st century, not the 20th.

i.e. there's a difference between measuring and naming, and it's not arbitrary, it's pure logic and maths.

Yes, you can say we're at the start of a new elapsed decade if we add a year at the very start of the epoch and call it "year 0".
But where else in measuring time do we call the first item "0", and add 1 to the total ?

LWN's 2020 vision

Posted Jan 9, 2020 13:07 UTC (Thu) by tao (subscriber, #17563) [Link]

"But where else in measuring time do we call the first item "0", and add 1 to the total ?"

You mean except "It's 00:30, during the first hour of the day"?

LWN's 2020 vision

Posted Jan 2, 2020 12:52 UTC (Thu) by jezuch (subscriber, #52988) [Link] (5 responses)

But we do say things like "the first decade of the Xth century" in which case the boundary of the centuries and the decades become misaligned and this is driving me nuts!!!

;)

LWN's 2020 vision

Posted Jan 2, 2020 13:51 UTC (Thu) by mathstuf (subscriber, #69389) [Link] (4 responses)

That's fine. It might also be the last decade of the previous century at the same time :) . Does winter "belong" to the year in which it starts or the year with most of its days? Why do we almost always (in the US at least) list spring as the "first" season?

LWN's 2020 vision

Posted Jan 2, 2020 14:40 UTC (Thu) by pizza (subscriber, #46) [Link] (3 responses)

Because the growing season starts in the spring?

LWN's 2020 vision

Posted Jan 9, 2020 9:17 UTC (Thu) by Wol (subscriber, #4433) [Link] (2 responses)

> Why do we almost always (in the US at least) list spring as the "first" season?

Because, until a couple of hundred years ago, New Year's Day was the 25th March? I think it changed (in the Anglo-Saxon world) just before American Independence.

Incidentally, that's behind why October is named the 8th month etc etc - they were until two new months were stuck at the start of the year.

Cheers,
Wol

LWN's 2020 vision

Posted Jan 9, 2020 14:14 UTC (Thu) by amacater (subscriber, #790) [Link]

1752 should be the change for England (and, by extension) US at that stage. for fun - look at the calendar for September 1752.

March 25th was a quarter day - so that's when taxes fell due - and was the start of the legal new year because it was easier for judges to give up going on circuit and taking the courts around the country in the worst of the winter. January 1st was already established as New Years Day in some calendars in Europe.

A remnant of March 25th as quarter day is, allegedly, the ffact that the UK tax year runs until April 5th [March 25th + 11 days]

LWN's 2020 vision

Posted Jan 9, 2020 19:11 UTC (Thu) by chfisher (subscriber, #106449) [Link]

Actually no. The two months were stuck in as July and August September was 7, October was 8, November was 9 and December was 10. Julius Ceaser wanted a month and so did Augustus.