> Depends on whether you're measuring or counting.
You run into issues when using 1-based counting as well as measuring.
Our calendar years use 1-based counting, which results in things like "2020" being the "20th year" of the "21st century". If we used 0-based counting instead, we would call the current year "2019" and it would be "year 19" of "century 20".
Explanation of conventional year counting:
1st century began in year 1
2nd century began in year 101 (100 years later)
..
21st century began in year 2001
If you run the same sequence as above, but start counting from 0, you get seemingly much more sensible numbers (0, 0; 1, 100; 20, 2000; x, x*100...). I suspect most people probably think that the 21st century began in 2000 anyway.
It should also be noted that the use of the number 0 in general is relatively recent. The Roman numeral system (which was initially used for our year numbering) has no representation for it, as it was only used conceptually hundreds of years later. It seems to me that the main reason people count from 1 is historical.
Counting from 0, 2019 would still be the 19th year of the 21st century. I'm puzzled why you completely changed grammar to make it seem like counting from zero also solved the century mismatch. If anything it suggests that counting from 1 is more consistent. Then 2020 is year 20 of century 20.
But then 2000 becomes year 0 of century 20, which is confusing English. But "century 20" isn't great English anyway. Calendars should be 0-based like any other measuring tool. The 3rd minute of the 2nd hour of a marathon is 1:02. The 3rd day of the 2nd month of my marathon is 1/02. If that happens to be the 3rd day of the second month of the year, it's 2/03?
> Counting from 0, 2019 would still be the 19th year of the 21st century.
I think you meant to say the "20th" year (off-by-one error!), since 2000 would be the "1st" year under your grammatical assumptions.
I think it's safe to assume that if we conventionally counted from 0 instead of 1, we wouldn't refer to the initial thing as "first" (or "1st"). If we did maintain that construction, we would probably just refer to the initial century as the "0th century" and then 2019 would be the "19th year of the 20th century".
> But then 2000 becomes year 0 of century 20, which is confusing English.
I think it's only confusing because it's unconventional, not because there's something inherently more confusing about it. There have been plenty of languages that haven't even had counting systems that do anything more than "alone, pair, many" .. sure, you can find contexts where counting in general is confusing.
> The 3rd minute of the 2nd hour of a marathon is 1:02.
Right, under current 1-based counting convention, but the point of this discussion is that this inconsistency exists for basically no reason (or rather, historical reasons—look up the history of "0"). When people want to do arithmetic on ordinal numbers, they end up subtracting 1 to turn them into a zero-based natural number, then add 1 again to turn them back into an ordinal:
I suspect most off-by-one errors can indeed be seen as due to this inconsistency between conventional ordinals and the more arithmetic-friendly zero-based naturals. Again, since the former is simply convention, I claim it would be better if our convention were different.
It doesn't go from -1 to 1, it goes from 1 BCE to 1 CE. Negatives aren't used at all. Personally I think we should use zero and negative CE to extend backwards instead. So the year we currently refer to as 1 BCE becomes 0 CE, 2 BCE becomes -1 CE and N BCE becomes -N+1 CE.
That's because we don't count decades. We say we live in the third millennium, and in the 21st century, but nobody calls this the 203rd decade. Instead we call it based on a common property of all the years in the decade (the count of these years can be abbreviated as twenty-something).
You run into issues when using 1-based counting as well as measuring.
Our calendar years use 1-based counting, which results in things like "2020" being the "20th year" of the "21st century". If we used 0-based counting instead, we would call the current year "2019" and it would be "year 19" of "century 20".
Explanation of conventional year counting:
If you run the same sequence as above, but start counting from 0, you get seemingly much more sensible numbers (0, 0; 1, 100; 20, 2000; x, x*100...). I suspect most people probably think that the 21st century began in 2000 anyway.It should also be noted that the use of the number 0 in general is relatively recent. The Roman numeral system (which was initially used for our year numbering) has no representation for it, as it was only used conceptually hundreds of years later. It seems to me that the main reason people count from 1 is historical.