WEBVTT 00:00:25.899 --> 00:00:28.920 everybody and we're back this is food for thought 00:00:28.920 --> 00:00:31.660 thoughts if it were you season two and this is 00:00:31.660 --> 00:00:36.679 your host neogentrics it is 2020 everybody it 00:00:36.679 --> 00:00:40.740 is the 6th 7th i forgot what today is of February 00:00:40.740 --> 00:00:42.740 and it's three o 'clock in the morning as we 00:00:42.740 --> 00:00:45.880 always do today's topic is on leap years because 00:00:45.880 --> 00:00:50.679 2020 is in fact a leap year so for the first 00:00:50.679 --> 00:00:53.170 time in the last couple of years We get to have 00:00:53.170 --> 00:00:55.609 29 days in February, so don't let that throw 00:00:55.609 --> 00:00:57.469 you off. If it looks like your calendar doesn't 00:00:57.469 --> 00:01:00.049 make sense, no, you didn't buy a faulty calendar. 00:01:00.350 --> 00:01:03.509 There is, in fact, an extra day on Saturday. 00:01:04.469 --> 00:01:09.930 With that being said, what is a leap year? Let's 00:01:09.930 --> 00:01:14.890 start with that, shall we? A leap year, also 00:01:14.890 --> 00:01:19.989 known as an intercalinary year or a bisectal 00:01:19.989 --> 00:01:23.209 year. It's a calendar year containing an additional 00:01:23.209 --> 00:01:29.689 day, or in case of Lunasola calendars, a month. 00:01:30.219 --> 00:01:33.040 basically being added to the calendar year to 00:01:33.040 --> 00:01:36.579 synchronize with the astronomical or seasonal 00:01:36.579 --> 00:01:39.500 year with the way the seasons actually flow. 00:01:39.680 --> 00:01:41.939 You know, because seasons and astronomical events 00:01:41.939 --> 00:01:45.140 don't repeat in the whole number of days. And 00:01:45.140 --> 00:01:47.900 calendars that have the same number of days in 00:01:47.900 --> 00:01:51.040 each year drift over time with respect to the 00:01:51.040 --> 00:01:53.319 event that the year is supposed to track. You 00:01:53.319 --> 00:01:58.909 know, by inserting this extra day... or month 00:01:58.909 --> 00:02:01.609 in a year, that drift is automatically corrected 00:02:01.609 --> 00:02:04.349 and a year that is not a leap year is called 00:02:04.349 --> 00:02:07.230 a common year. It's one of the many things that 00:02:07.230 --> 00:02:10.509 exist that a lot of people aren't aware of. Now, 00:02:10.669 --> 00:02:12.789 there are two kinds of calendars with that being 00:02:12.789 --> 00:02:14.889 said. One is the Gregorian and the original, 00:02:15.069 --> 00:02:18.990 the Lunar. Each one has something special about 00:02:18.990 --> 00:02:20.849 them that makes them unique and different areas 00:02:20.849 --> 00:02:24.629 follow different calendars. And with that being 00:02:24.629 --> 00:02:26.610 said, leap years are handled differently in other 00:02:26.610 --> 00:02:29.949 countries. I'll cover what a Gregorian calendar 00:02:29.949 --> 00:02:31.870 is and what the lunar calendar is in another 00:02:31.870 --> 00:02:34.750 podcast. But for now, let's go ahead and talk 00:02:34.750 --> 00:02:55.409 about leap years. All right? All right, and we're 00:02:55.409 --> 00:02:58.979 back. So let's go ahead and tackle that why do 00:02:58.979 --> 00:03:01.740 we have leap years question. First things first, 00:03:01.900 --> 00:03:04.259 we need a leap year to keep our modern day Gregorian 00:03:04.259 --> 00:03:06.180 calendar in line with the Earth's revolutions 00:03:06.180 --> 00:03:08.599 around the sun. It takes Earth approximately 00:03:08.599 --> 00:03:14.219 365 .242189 days, or just 365 days to simplify, 00:03:14.580 --> 00:03:18.139 and 5 hours and 48 minutes and 45 seconds to 00:03:18.139 --> 00:03:20.159 basically circle around the sun. Don't ask me 00:03:20.159 --> 00:03:22.139 how they got this number, that's a whole other 00:03:22.139 --> 00:03:25.189 podcast for another day. this is what we call 00:03:25.189 --> 00:03:28.150 a tropical year and astronomers measure this 00:03:28.150 --> 00:03:31.430 from the march equinox however the gregorian 00:03:31.430 --> 00:03:35.050 calendar only has 365 days in a year if we didn't 00:03:35.050 --> 00:03:37.710 add a leap day on the 29th of february every 00:03:37.710 --> 00:03:40.469 four years we would lose almost six hours off 00:03:40.469 --> 00:03:44.770 every calendar year uh on its own after only 00:03:44.770 --> 00:03:47.389 a hundred years our calendar would be off by 00:03:47.389 --> 00:03:52.219 about 24 days you know it's something that they 00:03:52.219 --> 00:03:56.219 took into consideration. Leap year rules follow 00:03:56.219 --> 00:03:59.900 as such. We add a leap day on February 29th almost 00:03:59.900 --> 00:04:02.199 every four years. I say almost because it's not 00:04:02.199 --> 00:04:05.400 every single four years. The leap day is an extra 00:04:05.400 --> 00:04:10.460 intercalary day. We add it to the shortest month 00:04:10.460 --> 00:04:14.219 of the year, typically February. This now begs 00:04:14.219 --> 00:04:15.919 the question, how do they calculate the leap 00:04:15.919 --> 00:04:18.920 years? In the Gregorian calendar, There are three 00:04:18.920 --> 00:04:21.420 criteria that must be taken into account to identify 00:04:21.420 --> 00:04:24.379 leap years. The year can be divided by four. 00:04:25.240 --> 00:04:29.319 If the year can't be evenly divided by 100, if 00:04:29.319 --> 00:04:31.220 the year can be evenly divided by 100, sorry, 00:04:31.279 --> 00:04:34.259 it is not a leap year unless the year is also 00:04:34.259 --> 00:04:38.120 evenly divisible by 400. Then it is a leap year. 00:04:38.279 --> 00:04:40.339 And according to these rules, the years 2000, 00:04:41.160 --> 00:04:47.000 2400 are leap years. while 1800, 1900, 2100, 00:04:47.079 --> 00:04:51.920 2200, 2300, and 2500 are not leap years. The 00:04:51.920 --> 00:04:55.620 year 2000, however, is a special leap year, for 00:04:55.620 --> 00:04:59.180 the simple fact that it was unique as it was 00:04:59.180 --> 00:05:01.259 the first instance when the third criterion was 00:05:01.259 --> 00:05:03.879 used in most parts of the world, since the start 00:05:03.879 --> 00:05:06.079 of the tradition started with the Julian calendar 00:05:06.079 --> 00:05:09.300 as it transitioned to the Gregorian in 1582, 00:05:09.660 --> 00:05:13.980 which, like I said, I'll go into later. Last 00:05:13.980 --> 00:05:16.980 but not least, who invented leap years? That 00:05:16.980 --> 00:05:19.759 would be the Roman general Julius Caesar. He 00:05:19.759 --> 00:05:21.879 introduced the first leap year over 2 ,000 years 00:05:21.879 --> 00:05:24.500 ago, but the Julian calendar only had one rule. 00:05:24.699 --> 00:05:27.060 Any year evenly divisible by four would be a 00:05:27.060 --> 00:05:29.240 leap year, so this formula produced way too many 00:05:29.240 --> 00:05:32.060 leap years. Still, it was not corrected until 00:05:32.060 --> 00:05:34.600 the introduction of the Gregorian calendar, which 00:05:34.600 --> 00:05:38.639 was 1 ,500 years later. Basically the ancient 00:05:38.639 --> 00:05:40.759 Roman calendar added an extra month every few 00:05:40.759 --> 00:05:43.819 years to maintain correct seasonal changes Which 00:05:43.819 --> 00:05:45.959 is really similar to what we call the Chinese 00:05:45.959 --> 00:05:50.019 leap year or the lunar year So there's a lot 00:05:50.019 --> 00:05:51.839 of stuff that go into this and a lot of facts 00:05:51.839 --> 00:06:17.300 that need to be known Now that I covered that, 00:06:17.519 --> 00:06:20.519 and I mentioned what the main difference between 00:06:20.519 --> 00:06:24.579 leap year and a common year is, we know that 00:06:24.579 --> 00:06:27.339 the next leap day is basically February 29, 2020. 00:06:27.819 --> 00:06:31.560 Our last leap year was February 29, 2016. Now, 00:06:31.699 --> 00:06:34.540 the Gregorian calendar year consists of 52 weeks 00:06:34.540 --> 00:06:37.100 and one day. Because of this, January 1st and 00:06:37.100 --> 00:06:39.420 31st of a common year are always on the same 00:06:39.420 --> 00:06:42.660 day of the week. And the next year begins on 00:06:42.660 --> 00:06:46.550 the next day of the week. For instance, the common 00:06:46.550 --> 00:06:51.389 year 2021 begins and ends on a Friday. Consequently, 00:06:51.610 --> 00:06:54.810 2022 starts and ends on a Saturday, while 2023 00:06:54.810 --> 00:06:59.189 starts and ends on a Sunday. Out of every 400 00:06:59.189 --> 00:07:02.129 years in the Gregorian calendar, 303 years are 00:07:02.129 --> 00:07:06.290 common years. The rest, 97 years, have an intercalary 00:07:06.290 --> 00:07:10.910 day, the leap year day, making them 366 days 00:07:10.910 --> 00:07:14.410 long. which is, in a way, different from what 00:07:14.410 --> 00:07:18.269 we call a tropical year. Common years and other 00:07:18.269 --> 00:07:20.470 calendars are split up a little bit differently 00:07:20.470 --> 00:07:23.410 as they're set up differently. The Hebrew calendar, 00:07:23.550 --> 00:07:26.769 which is the one I mainly use, which is basically 00:07:26.769 --> 00:07:29.870 a lunar -solar calendar, has 12 months in a common 00:07:29.870 --> 00:07:35.029 year, which we can have anywhere from 353 to 00:07:35.029 --> 00:07:39.800 355 days. With the leap years in such a calendar 00:07:39.800 --> 00:07:44.839 having 383 to 384 days and 13 months, that means 00:07:44.839 --> 00:07:47.439 we get an extra month. The Chinese calendar, 00:07:47.540 --> 00:07:49.819 however, is a common year in the Chinese calendar. 00:07:52.519 --> 00:07:55.699 In a way saying that, you know, it's also a lunar 00:07:55.699 --> 00:07:59.500 calendar as well. They have 12 months, 353 to 00:07:59.500 --> 00:08:02.670 355 days. A month in the Chinese common year 00:08:02.670 --> 00:08:04.709 corresponds to the cycle of the moon, so from 00:08:04.709 --> 00:08:07.370 full moon to full moon. Because of this, a regular 00:08:07.370 --> 00:08:10.829 month can have 29 or 30 days. Leap years in the 00:08:10.829 --> 00:08:13.050 Chinese calendar, however, have 13 months, so 00:08:13.050 --> 00:08:16.910 they add an extra month. Next is the Islamic 00:08:16.910 --> 00:08:20.209 calendar. The common years in the Islamic calendar, 00:08:20.310 --> 00:08:23.209 which is purely a lunar calendar, have 354 days 00:08:23.209 --> 00:08:26.430 divided into 12 months. Some months have 30 days 00:08:26.430 --> 00:08:29.930 while others have 29, similar to ours. similar 00:08:29.930 --> 00:08:32.590 to the Gregorian calendar anyway. 11 out of 30 00:08:32.590 --> 00:08:35.990 years are Islamic leap years. So where the leap 00:08:35.990 --> 00:08:38.230 year has 30 days in the last month of the year, 00:08:38.429 --> 00:08:41.870 making the Islamic leap year 355 days, different 00:08:41.870 --> 00:08:43.590 communities follow different rules about how 00:08:43.590 --> 00:08:46.190 to space the leap years in the 30 year cycle. 00:08:47.610 --> 00:08:50.590 Last but not least is the Indian calendar. Both 00:08:50.590 --> 00:08:53.509 solar and lunar solar calendars with regional 00:08:53.509 --> 00:08:57.149 variations are used in Indian or India subcontinent 00:08:57.149 --> 00:08:59.909 areas. and the solar calendar, the common years, 00:08:59.990 --> 00:09:04.629 again, 365, with 10 leap years of 366 days each 00:09:04.629 --> 00:09:09.070 in a cycle of 39 years. However, unlike the Gregorian 00:09:09.070 --> 00:09:12.450 calendar, the Indian solar calendar, also known 00:09:12.450 --> 00:09:20.250 as the Narayana, I'm pronouncing that the best 00:09:20.250 --> 00:09:22.610 I can, there is no fixed rule as to which year 00:09:22.610 --> 00:09:25.330 in the cycle will be a leap year. So two kinds 00:09:25.330 --> 00:09:27.070 of lunar solar calendars are used in the Indian 00:09:27.070 --> 00:09:30.269 system. The Amanta, in which the month runs from 00:09:30.269 --> 00:09:33.809 new moon to new moon, and the Paramanta, which 00:09:33.809 --> 00:09:38.350 runs from full moon to the next full moon. The 00:09:38.350 --> 00:09:41.090 common year in the Amanta calendar is 12 months 00:09:41.090 --> 00:09:44.889 long and is 29 days long, on average, and then 00:09:44.889 --> 00:09:48.909 the year is 354 days. Seven intercalary months, 00:09:49.169 --> 00:09:53.889 called the Adhikmas, are added at different intervals 00:09:53.889 --> 00:09:57.389 to the year in a 19 year cycle so go figure now 00:09:57.389 --> 00:10:00.110 keep in mind like i mentioned before every calendar 00:10:00.110 --> 00:10:02.769 type is different based off of the region that 00:10:02.769 --> 00:10:05.509 you're in you know and everyone looks at it differently 00:10:05.509 --> 00:10:08.470 this is why i try to make a point of covering 00:10:08.470 --> 00:10:10.610 most of the basic information that a lot of people 00:10:10.610 --> 00:10:29.179 don't know All right, everybody. The last thing 00:10:29.179 --> 00:10:33.340 I want to cover in this talk about lunar year, 00:10:33.460 --> 00:10:37.740 as far as the leap year is concerned, is what 00:10:37.740 --> 00:10:39.820 is a tropical year and how long does that last? 00:10:39.899 --> 00:10:42.519 It's typically called a solar year. A year is 00:10:42.519 --> 00:10:46.570 never 365 days long. A tropical year is also 00:10:46.570 --> 00:10:49.789 known as a solar year, as an astronomical year, 00:10:49.970 --> 00:10:56.250 or an equinoctial year, is basically an average 00:10:56.250 --> 00:10:59.909 approximately 365 days, 5 hours, 48 minutes, 00:10:59.970 --> 00:11:03.429 and 45 seconds long, or as I mentioned before, 00:11:03.669 --> 00:11:09.450 365 .24219 days. A tropical year can be measured 00:11:09.450 --> 00:11:14.679 from either the vernal or autumnal equinox. to 00:11:14.679 --> 00:11:17.980 the next one, or from summer to winter solstice 00:11:17.980 --> 00:11:23.480 to the next one. On the website timeanddate .com, 00:11:23.559 --> 00:11:25.700 we calculate on a tropical year from the March 00:11:25.700 --> 00:11:29.120 equinox to the next March equinox. And as a result, 00:11:29.200 --> 00:11:31.820 our leap day synchronizes with the calendar accordingly. 00:11:32.100 --> 00:11:35.200 Although a common year has 365 days, in today's 00:11:35.200 --> 00:11:38.320 Gregorian calendar, we add a leap year day nearly 00:11:38.320 --> 00:11:40.399 every four years to stay in sync with the tropical 00:11:40.399 --> 00:11:45.120 year. So with that being said, without the correct 00:11:45.120 --> 00:11:47.720 amount of leap years, our calendar would quickly 00:11:47.720 --> 00:11:50.179 become out of sync. This happened to the Julian 00:11:50.179 --> 00:11:51.899 calendar, as I mentioned before, because they 00:11:51.899 --> 00:11:55.080 had way too many leap years. And eventually they 00:11:55.080 --> 00:11:56.759 had to replace it with the Gregorian calendar. 00:11:57.299 --> 00:12:00.019 Now keep in mind, it can vary by 30 minutes. 00:12:00.360 --> 00:12:02.799 The exact length of a tropical year can vary 00:12:02.799 --> 00:12:05.320 up to about half an hour to an hour. For instance, 00:12:05.440 --> 00:12:08.440 the tropical year, for example, 2032, will last 00:12:08.440 --> 00:12:13.539 longer than 365 days and 6 hours. in 2027 however 00:12:13.539 --> 00:12:17.539 will only have last 365 days 5 hours and 39 minutes 00:12:17.539 --> 00:12:21.580 each year is different there's websites that 00:12:21.580 --> 00:12:23.360 keep track of this on a chart so you can see 00:12:23.360 --> 00:12:25.860 what it looked like from 2000 all the way up 00:12:25.860 --> 00:12:31.019 to the current 2020 in march now keeping all 00:12:31.019 --> 00:12:33.279 of this in mind there's a lot of stuff that comes 00:12:33.279 --> 00:12:36.000 with everything that i've mentioned And a lot 00:12:36.000 --> 00:12:37.820 of this information you can find on timeanddate 00:12:37.820 --> 00:12:40.019 .com. I won't say that I knew this by heart. 00:12:40.860 --> 00:12:42.919 But keep in mind that a lot of this information 00:12:42.919 --> 00:12:44.700 is available out there for a lot of people to 00:12:44.700 --> 00:12:47.039 get. But not everyone knows this. You need to 00:12:47.039 --> 00:12:49.240 know about time. You need to know about how it 00:12:49.240 --> 00:12:52.899 works. These are important skills people need 00:12:52.899 --> 00:12:55.820 to know when they don't know. You need to know 00:12:55.820 --> 00:12:57.419 how to read weather. You need to know the time 00:12:57.419 --> 00:13:00.899 zone differences. Stuff like this. This stuff 00:13:00.899 --> 00:13:05.220 matters. With that being said, I thank you guys 00:13:05.220 --> 00:13:07.519 for listening. Enjoy the rest of your day. Again, 00:13:07.600 --> 00:13:09.299 this has been Food for Thought. Thoughts if it 00:13:09.299 --> 00:13:13.379 were you. I'm your host, Neogentrix. Have a great 00:13:13.379 --> 00:13:13.940 rest of your day.