1 00:00:00,233 --> 00:00:03,233 I told you in the last video on calendar notation that 2 00:00:03,233 --> 00:00:08,367 regardless of whether you're using BC/AD or BCE and CE, 3 00:00:08,367 --> 00:00:11,033 that there is no year zero, 4 00:00:11,033 --> 00:00:16,167 that we had 1BC and then we had that theoretical birth of Jesus 5 00:00:16,167 --> 00:00:22,767 and most historians don't think he was born right exactly on 1 January 1AD 6 00:00:22,767 --> 00:00:24,567 but there is no year zero 7 00:00:24,567 --> 00:00:31,967 right after that you go from 31 December 1BC to 1 January 1AD. 8 00:00:31,967 --> 00:00:33,633 There's no year zero. 9 00:00:33,633 --> 00:00:36,300 And despite the fact that I emphasized in the last video, 10 00:00:36,300 --> 00:00:40,033 I didn't take that into consideration when I calculated 11 00:00:40,033 --> 00:00:47,700 how many years there were between Plato's birth and Columbus' discovering of the New Wolrd 12 00:00:47,700 --> 00:00:50,233 The reason why I didn't take that into consideration 13 00:00:50,233 --> 00:00:57,767 is that the year 1492, whether you want to call it AD 1492, Anno Domini 1492, 14 00:00:57,767 --> 00:01:01,567 whether you wanna call it that or you wanna call it 1492 in the Common Era 15 00:01:01,567 --> 00:01:07,500 it's not 1492 years since the theoretical birth of Jesus, 16 00:01:07,500 --> 00:01:10,567 which we know is not the actual birth. He was probably born before that. 17 00:01:10,567 --> 00:01:15,767 It is 1491 years since the birth of Jesus. 18 00:01:15,767 --> 00:01:22,233 And to think about it this way, let's just assume the theoretical date we're talking about here 19 00:01:22,233 --> 00:01:26,433 or this theoretical event, this kind of birth of Jesus that our calendars evolve around 20 00:01:26,433 --> 00:01:41,433 If we talk about 1 January, let's think about it this way, so 1 January in the Common Era, 21 00:01:41,433 --> 00:01:46,300 how long is that since the birth of Jesus? It's not 1 year. 22 00:01:46,300 --> 00:01:52,100 You wouldn't just look at this and say it's been 1 year, because this is theoretically the day that he was born. 23 00:01:52,100 --> 00:01:57,233 So this is zero years, or almost zero years since that theoretical birth of Jesus. 24 00:01:57,233 --> 00:02:12,367 Another way to think about it is: How long after 1 January 1BCE, and I can call this AD and I can call this BC, 25 00:02:12,367 --> 00:02:14,833 what's the time difference between these two days? 26 00:02:14,833 --> 00:02:20,033 So, the way I calculated it before I said "Oh, this is one year after that theoretical birth" that's wrong. 27 00:02:20,033 --> 00:02:21,767 This is during that theoretical birth. 28 00:02:21,767 --> 00:02:26,700 The way I did in the last video, I said "Oh, this is one year after, this is one year before 29 00:02:26,700 --> 00:02:28,967 you add them together and you would get two." But that's wrong. 30 00:02:28,967 --> 00:02:30,967 Because there is no year zero. 31 00:02:30,967 --> 00:02:41,833 So 1 January 1AD, or 1CE is right over here and then 1 January 1BCE is exactly one year before that. 32 00:02:41,833 --> 00:02:45,900 So there's only one year. One year difference. 33 00:02:45,900 --> 00:02:50,033 And the reason why the math is strange is there is no year zero. 34 00:02:50,033 --> 00:02:53,900 If there was a year zero, then my calculation in the last video is correct. 35 00:02:53,900 --> 00:03:01,100 So really, the way that you would calculate the time between Plato's birth at 428BC 36 00:03:01,100 --> 00:03:06,167 and Columbus sailing across the Atlantic in 1492 37 00:03:06,167 --> 00:03:12,967 you would say "ok, this is 428 years before that theoretical birth of Christ 38 00:03:12,967 --> 00:03:18,300 but this isn't 1492 years after that theoretical birth. 39 00:03:18,300 --> 00:03:23,633 This is 1492 minus one. So what you do is you add these two numbers 40 00:03:23,633 --> 00:03:28,300 this is 428 before, this is 1492 minus one years after 41 00:03:28,300 --> 00:03:34,433 so you would add them and then subtract one, so the correct answer - this is the correction part 42 00:03:34,433 --> 00:03:38,833 it isn't 1920 years between Plato's birth and Columbus. 43 00:03:38,833 --> 00:03:42,700 It is, we wanna subtract one from that, 44 00:03:42,700 --> 00:03:48,967 it is 1920 minus one years, so that is 1919 years. 45 00:03:48,967 --> 00:03:53,167 The same way that the difference between 1AD and 1BCE, 46 00:03:53,167 --> 00:03:57,567 you would say, you could almost do this in positive and negative numbers, you say: 47 00:03:57,567 --> 00:04:01,367 "Oh, this is positive one minus negative one and that would give me two, but there is no zero 48 00:04:01,367 --> 00:04:06,033 so you just subtract another one, so this is exactly one year difference. 49 00:04:06,033 --> 00:04:10,033 Just wanted to clarify that. That's what that "no year zero" stuff does.