Had a familiar discussion today about whether or not the millennium started on January 1st, 2000, or on January 1st, 2001. (Spoiler Alert: It was 2001.)
General rule of thumb: You can tell what millennium / century / decade you are in by taking the relevant digit and rounding up.
For example: What decade is the year 39 AD in?
- Decade 1: 1-10
- Decade 2: 11-20
- Decade 3: 21-30
- Decade 4: 31-40
Or you can treat 39 as 3.9, round up to 4. 4th decade.
Same thing with centuries: What century is the year 1675 in? The 17th century. Because 16.75 rounded up is 17.
What century is the year 1600 in? The 16th. Because 16.00 rounded up is 16.
Same thing with millennia. 2000 is in the second millenium (2.000 rounded up is 2). 2001 is in the third millennium (2.001 rounded up is 3).
I think you’re mistaken, here. When the year number rolls over to 2000, it marks that 2000 years have passed, and we are beginning the 3rd millennium.
Or using your same logic, January 2nd of 2000 is essentially year 2000.0027… which rounds up to 3000. 3rd millennium. Other examples would be soccer goals (a goal at time 38:12 is scored in the 39th minute) or a person’s current year of life (Someone who is 27 years old is living in their 28th year).
BurgerBeast wrote: “When the year number rolls over to 2000, it marks that 2000 years have passed…”
Except that’s not true.
Let’s put it this way: On January 1st, 1 AD how many years had passed since the beginning of the millennium? The answer is 0 years. On January 1st, 2 AD how many years had passed? The answer is 1 year. On January 1st, 3 AD how many years had passed? The answer is 2 years.
You’ll notice that the answer is always 1 less than the current year because year you are currently in obviously has not passed yet. (For the same reason that you cannot be passed by a car that you are sitting inside of.)
So on January 1st, 2000 AD how many years had passed? 1999.
BurgerBeast wrote: “Other examples would be soccer goals (a goal at time 38:12 is scored in the 39th minute)”
Because on the game clock you count from 0. When you are halfway through the first minute of the game you are at 0.5 minutes of elapsed time. When you are halfway through the first year AD you are at 1.5 on your calendar.
The common rejoinder here is that we could just add a year 0 to the calendar. We could do that, of course, but then we’d currently be living in 2015, not 2016. Maybe there’s some alternate universe where that’s true. But in this universe (where it’s currently 2016), the third millennium started on January 1st, 2001.
BurgerBeast wrote: “Or using your same logic, January 2nd of 2000 is essentially year 2000.0027…”
Please don’t lie about what I said. It’s rude and it’s stupid.
Clearly the calendar wasn’t invented by a programmer or we’d have 0 ADBC and this would be much more intuitive.
It amazes me the sheer number of people who will argue with this simple fact. Mr. Alexander is correct.
The numbering system of our calendar was adopted to count the number years since Christ was born (although the exact date remains uncertain). The year 2016 AD (Anno Domini) connotes: “the two-thousand sixteenth year of the Lord”. 1 AD (never actually called that while it was happening) is supposed to be “the first year of the Lord”.
As the Reverend Richard J. Mackin wrote, your tenth finger is the last finger on your hands, not the first finger on your friend’s hand.
When my son was born some joker said the times was midnight. The hospital changed his birthday three times over the next day: from the 5th to the 6th then back to the 5th. Much like the millennium, 2400 is the last minute of the day and 0001, or 12:01 am, is the first of the next!
The “which day does the stroke of midnight belong to” thing used to be one of the great philosophical conundrums of my pre-teens. But, yeah, once you phrase it as a 24-hour clock it becomes really abundantly clear which day 24 o’clock belongs to.
Hm. Random idea for an alien culture: Clock that counts down how much time is left in the day instead of counting up.
The alien clock thing is interesting, especially in a situation where the players could mistake it for a countdown to something major like a bomb going off. Although perhaps the realisation it was just the next day would be a bit of a let down!
As for the topic at hand, it’s hard to add to what has already been said, although I can see why it might be confusing for some.
Random idea riffing on a random idea:
Alien culture with a calendar counting down to the end of the world.
Is 00:00 not the start of the new day? As in the very millisecond after midnight?
But there is no 2400 hours, it goes from 2359 directly to 0000. You guys are forgetting to count 0 in all your arguments. In the “ten fingers” argument by Odrook he is right because we don’t start counting fingers with zero. In time we do, so there was a year zero (even if it wasn’t called that back then). It’s like if we still had ten fingers, but called them 0-9 instead of 1-10.
Also, no, you absolutely do not round up or down to find which decade or millennium you are in. I was born in 1987, which is absolutely not the 90s — the same way I can’t say it’s tomorrow at 1600 this afternoon, and 1995 is not in the 21st century. It’s like birthdays, you turn a year older on the day of your birth, not the day after.
Hm. Looks like some versions of the 24 hour clock use 24:00 and some use 00:00. (And, apparently, some use both. It looks like my juvenile existential crisis must continue unabated when it comes to the identity of midnight.
Still no Year 0 AD, though. It doesn’t exist.
Jordan wrote: “I was born in 1987, which is absolutely not the 90s”
Now you’re mixing two different nomenclatures. Or are you also claiming that 1987 is part of the 19th century because it is indubitably part of the 1900s?
Similarly, the year 2000 is unquestionably part of the “2000s”, just as it is also unquestionably part of the 20th century and the second millennium.
Jordan wrote: “1995 is not in the 21st century”
Hot tip: 19.95 rounded up to the next whole number is not 21.
If you were born in 1987, you were born in the 9th decade of the 20th century of the 2nd millennium. Because 00-09 are the first decade, 00-99 the first century and 000-999 the first millennium.
It’s true there was no year 0AD though, same way there’s no 0th of March, guys who made calendars weren’t programmers and decided it should go from 1 BC(The year before Christ) straight to 1 AD (1st year of our Lord).
Also 00:00 is correct and 24:00 incorrect, because otherwise you end up with the thoroughly confusing time of 24:59 which means you are counting nearly 25 hours in a day. (Disclaimer: This may be wholly made up of my opinion)
@jordan: The only system of time measurement that begins with 0 is the 24-hour clock, which is a relatively recent innovation. The first day of the year is not January 0th.
Yeah, I noticed my mistake shortly after I posted, but didn’t want to double post.
@Wyvern: so do all timer-systems. For example, a newborn baby is not considered 1 year old in North America. He/she is considered zero years old, living his/her first year. Likewise, in my previous post I mentioned sport timers that start at zero minutes.
@Justin Alexander: well I completely overlooked the bit where you accused me of being a liar and rude.
You said:
“BurgerBeast wrote: “Or using your same logic, January 2nd of 2000 is essentially year 2000.0027…”
Please don’t lie about what I said. It’s rude and it’s stupid.”
Whoa. I didn’t lie at all. Nor was I being rude. I was definitely being stupid, though. I was applying my misconception (not recognizing that absent a year 0, the a point within year 23 is in fact the 23rd year) and your logic (the same logic I was applying but to an incorrect assumption, and sound logic at that).
I think it’s pretty evident, in what I wrote (and you explained it well in your answer), where I was going wrong (not realizing that 1 BCE is the first year), so pointing out that the second day of 2000 marks the passage of 2000.027 years is exactly the mistake I was making, instead of realizing it was 1999.027. So I was using your logic, correct logic… but correct logic applied to my misconception led to the wrong conclusion.
@ BurgerBeast: Poor wording on my part. When I said “system of time measurement” I wasn’t thinking about oven timers or stopwatches; I meant, for lack of a better term, calendrical systems. That is, a system you would use to describe what hour/day/month/year it is. Since the question of when a millennium begins or ends is a obviously a calendrical issue, we should refer to calendrical methods of measuring time to determine the answer, and whether or not you count up or down to zero when using a stopwatch or timer is irrelevant. (Also, I’d point out that people don’t usually talk about infants being zero years old; they would say that their child is “three weeks” or “eight months” old, i.e. they’re still counting up from one.)
That said, I think this is a fruitless argument. While everything that Justin has said is technically correct, I don’t think it’s going to have any impact on society; people will still celebrate the next “turn of the century” on January 1st, 2100.
@Wyvern: fair enough.
Nitpick: even considering that babies are never referred to as zero years old, the months/weeks/days system doesn’t start at 1. It starts at 0. A baby is “not even a day old” in its first day, and then “one day old” in its second day, “one week old” in its second week, “one month old” in its second month, etc.
This is the thinking that led me to my misconception, even though I’ve resolved this in my head a few times before.