# Gregorian vs Julian calendar for dummies **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2006, 9:14pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849 "2006-02-23T21:14:24Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [February 24, 2006, 2:29am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/21 "2006-02-24T02:29:29Z")
> [@Kimstu](#): > > Well, how much is a little bit? Sure, they **approximately** coincide…as in, the period we call a “year” contains approximately 365.25 of the periods we call a “day”. But not exactly. > > They don’t match up with any nice, convenient, round-number ratio like 360.0000 days per year, and they never did (unless you’re a Velikovskian or something). The almost coincidence of the 360-degree circle and the 365-day year could help explain how the 360 degree thing got going back in the days when fractions weren’t well liked or appreciated. It has also sparked speculation that in ancient days (early in human knowledge) there were actually 360 days in the year and that somehow things changed so that it took an extra 5 days since those olden times for the earth to make its yearly trip around the sun. In fact there are any number of theories to support odd findings around the planet where things don’t square up with our current-day understanding of astronomical details. ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [February 24, 2006, 3:04am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/22 "2006-02-24T03:04:53Z")
But isn’t it true that the 360 degree circle was based on the rounding down of the yearly orbit circle? Of course, 360 degrees is a really convenient number in terms of finding useful divisions, but isn’t the 24 hour clock based on that 360, which is in turn based on the 360 (365) days of the year? ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [February 24, 2006, 3:08am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/23 "2006-02-24T03:08:06Z")
> [@alice\_in\_wonderland](#): > > Wow. This is really wild stuff. > > Ok, so lets say that I want to order a crate of oranges (whatever) from a supplier in Ethiopia. I call him up and say I need the oranges by March 15th, and he then does the mental gymnastics required to figure out that’s about August 10th or something, and ship the goods. You call him up? On what? Think, person, think! You’re dealing with people by letter carried by boat or horse. Everything took place at a slower pace then and the exact time of day or nomenclature for the current month or year was totally irrelevant. As Ethiopia doesn’t grow oranges particuularly, let’s talk coffee. If you run a coffee shop in, say, Vienna you go down to the commercial district and see what there is available right there and then. You supplier says I don’t have what you want right now, but I expect a shipment some time in the next 3 months. You knew this was likely so you went down there before you needed to anyway, and place your order, Your supplier gets what shipments he can when he can. The occasional ship sinks or is taken over by pirates, this is all part of the commercial risk of import. The Genoese coffee importer gets shipments on a sporadic basis from perhaps Egypt or Lebanon, who gets it from Arabia, who gets it from Ethiopia. What the current calendar looks like in Ethiopia is totally irrelevant to you. ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 3:10am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/24 "2006-02-24T03:10:20Z")
This is just getting more and more interesting. Ok, so how did the pope come up with all this info to develop his own calendar? I’m guessing that their were a bunch of astronomers and monks and things doing research, and they presented their findings and the pope thought it was cool. Or was it that he just wanted his name on a calendar? And doesn’t it seem odd that it if the earth travels around the sun in about 365 days they would round it down to apply to a circle? I would have thought that messing with a system that had been “devleoped by god” - that is, the earth’s rotation of the sun - would sort of go against most popely things. But on the other hand, what the hell do I know? ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [February 24, 2006, 3:11am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/25 "2006-02-24T03:11:04Z")
> [@GuanoLad](#): > > But isn’t it true that the 360 degree circle was based on the rounding down of the yearly orbit circle? > > Of course, 360 degrees is a really convenient number in terms of finding useful divisions, but isn’t the 24 hour clock based on that 360, which is in turn based on the 360 (365) days of the year? No. Even the Babylonians, from whom both the 360 degree circle and the 60 minute hour come, knew that 360 does not equal 365. 60 was a special number for them (precisely because it was so wonderfully divisible by so many smaller numbers) and they used it whenever they could. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [February 24, 2006, 3:11am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/26 "2006-02-24T03:11:50Z")
> [@GuanoLad](#): > > But isn’t it true that the 360 degree circle was based on the rounding down of the yearly orbit circle? > > Of course, 360 degrees is a really convenient number in terms of finding useful divisions, but isn’t the 24 hour clock based on that 360, which is in turn based on the 360 (365) days of the year? I’d like to hear your reasoning on the 24-hour and 360-degree connection. Other than 24 X 15 = 360 and 15 X 2 = 30, what other relationship(s) do you know of? I have heard of the base-60 system in older math systems, so the fact that 60 and 360 are commensurate has always made intuitive sense. ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 3:12am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/27 "2006-02-24T03:12:30Z")
> [@Askance](#): > > You call him up? On what? Think, person, think! . I am thinking, and apparently you’re not, because: a) the Ethiopian calendar is still being used today b) they have phones in Ethiopia today as well. So if I want to order some coffee from Ethiopia tomorrow, I’m gonna call someone, ask for it by April 3rd, and they’re going to have to do some figuring as to when the hell that is. No? ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 3:15am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/28 "2006-02-24T03:15:14Z")
> [@alice\_in\_wonderland](#): > > a) the Ethiopian calendar is still being used today At least according to the link in post #8 of this thread, that is. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [February 24, 2006, 3:30am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/29 "2006-02-24T03:30:36Z")
> [@alice\_in\_wonderland](#): > > So if I want to order some coffee from Ethiopia tomorrow, I’m gonna call someone, ask for it by April 3rd, and they’re going to have to do some figuring as to when the hell that is. Yes they are, as they do every hour of the day, as almost all of their customers will be from outside Ethiopia. How is this a problem or concern for you? The USA used to have hundreds of timezones, almost one per county. The railways produced these huge volumes so people could work out when a train they got on would arrive somewhere, and meet another train going somewhere else. While a pain, people coped. Eventually pressure made the goverment formalise timezones down to four across the continental US. What makes you think that modern Ethiopians are less capable of dealing with this than Americans over 100 years ago? Business seems to cope with timezone and DST changes around the world, why is it that you think a calendar change would be so much more difficult? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [February 24, 2006, 3:45am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/30 "2006-02-24T03:45:40Z")
> [@](#): > > Ok, so how did the pope come up with all this info to develop his own calendar? I’m guessing that their were a bunch of astronomers and monks and things doing research, and they presented their findings and the pope thought it was cool. Or was it that he just wanted his name on a calendar? You are right about the astronomers and mathematicians working for the pope. However, they were not just freelancers to whom the pope decided to grant an audience, one day; they were working for the pope. Many of the dates in the ecclesiastical calendar are tied to astronomical events. (Particularly Easter and the feasts that are reckoned from Easter (Ash Wednesday, Ascension Thursday, Pentecost, etc.) are **based** on astronomical events.) With the inherent error in the calendar commissioned by Julius Caesar, the Spring equinox (used in calculating Easter) and the Winter Solstice (which coincided with Christmas season celebrations) began to occur more than a week earlier on the calendar than they “occurred” according to the sun and stars–with each feast getting further out of place all the time (or, at least, every couple of centuries). The purpose of the correction to the calendar was to prevent Spring, (for example) from drifting into February, at some point. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [February 24, 2006, 3:51am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/31 "2006-02-24T03:51:18Z")
> [@](#): > > Wowsers. It probably shouldn’t, but this totally blows my mind. > > So, am I to assume that trade between countries using different date systems was minimal, or were people just not that bothered by having packages arive 24 hours, or 2 weeks later ('cus, of course FedEx was around in those times…) > > Are there any countries that currently use a calendar different than the “regular” one? I know that the Chinese celebrate New Year on a rotating basis that has nothing much to do with the Gregorian calendar. > > This is really fascinating. The British Empire (along with the future United States) switched over to the Gregorian calendar in 1752. But other countries waited even longer. Russia didn’t witch until 1918 (which is why the February and October Revolutions occurred in what is now March and November) and Greece didn’t make the switch until 1923. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [February 24, 2006, 3:57am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/32 "2006-02-24T03:57:43Z")
Reading on this subject, I see that Taiwan supposedly uses the same months and days as the Gregorian calendar but not the same years. They base the calendar on the founding of the Republic of China in 1912 - so it’s officially the year 94. Can anyone confirm this is true? ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [February 24, 2006, 9:36am UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/33 "2006-02-24T09:36:49Z")
> [@Askance](#): > > Eventually pressure made the goverment formalise timezones down to four across the continental US. Nitpick, but it was the railroads themselves who did this, at noon on November 18, 1883. Lots of businesses & people started using it soon after, but it was 35 years later before Congress got around to officially formalizing it. See [Seite nicht gefunden - Fehler 404 - FREMO - Freundeskreis Europäischer Modelleisenbahner e.V.](http://www.fremo.org/betrieb/timezone.htm) for more details. ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 8:53pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/34 "2006-02-24T20:53:00Z")
> [@Askance](#): > > Yes they are, as they do every hour of the day, as almost all of their customers will be from outside Ethiopia. How is this a problem or concern for you? Dude, chill out. It’s not much concern, I just find it interesting. Apparently you take this calendar business very seriously. Good for you. Quit killing my buzz. ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 8:54pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/35 "2006-02-24T20:54:48Z")
> [@Little Nemo](#): > > Reading on this subject, I see that Taiwan supposedly uses the same months and days as the Gregorian calendar but not the same years. They base the calendar on the founding of the Republic of China in 1912 - so it’s officially the year 94. Can anyone confirm this is true? Wow - so if it’s 1994 in Taiwan, does that mean in 6 years they’re going to have to live the Y2K problem all over again? Seriously - I suppose a lot of computers are made in Taiwan - do they just make two types? One with the Tiwanese year, and one for everyone else? (And I suppose one for customers in Ethiopia that want their calendar) ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [February 24, 2006, 9:40pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/36 "2006-02-24T21:40:02Z")
> [@alice\_in\_wonderland](#): > > > [@Little Nemo](#): > > > > Reading on this subject, I see that Taiwan supposedly uses the same months and days as the Gregorian calendar but not the same years. They base the calendar on the founding of the Republic of China in 1912 - so it’s officially the year 94. Can anyone confirm this is true? > > Wow - so if it’s 1994 in Taiwan, does that mean in 6 years they’re going to have to live the Y2K problem all over again? Seriously - I suppose a lot of computers are made in Taiwan - do they just make two types? One with the Tiwanese year, and one for everyone else? (And I suppose one for customers in Ethiopia that want their calendar) According to what **Little Nemo** said, it’s not **19** 94 in Taiwan, its 94, as in 0094. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [February 24, 2006, 11:02pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/37 "2006-02-24T23:02:48Z")
Taiwan is a major trading partner with all the developed countries in the world. It is definitely 2006 there. The year “94” just means that the Republic of China was established 94 years ago (1910). According to the traditional Chinese calendar, its the year 4703, but no one really pays any attention to that calendar. If you want some planetary “spookiness”, how about the fact the the moon is just the right size to block out the sun during a total solar eclipse here on Earth? ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 24, 2006, 11:14pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/38 "2006-02-24T23:14:10Z")
> [@FatBaldGuy](#): > > According to what **Little Nemo** said, it’s not **19** 94 in Taiwan, its 94, as in 0094. So in 6 years, will they have to worry about the Y1C bug? ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [February 24, 2006, 11:21pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/39 "2006-02-24T23:21:50Z")
> [@Mangosteen](#): > > If you want some planetary “spookiness”, how about the fact the the moon is just the right size to block out the sun during a total solar eclipse here on Earth? Are you trying to make my head explode? 😉 ---
**Author:** ![GorillaMan](https://avatars.discourse-cdn.com/v4/letter/g/50afbb/32.png) [@GorillaMan](https://boards.straightdope.com/u/GorillaMan)\ **Post date:** [February 24, 2006, 11:25pm UTC](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849/40 "2006-02-24T23:25:37Z")
> [@Mangosteen](#): > > If you want some planetary “spookiness”, how about the fact the the moon is just the right size to block out the sun during a total solar eclipse here on Earth? Nice - it’s like Douglas Adams’ description of a puddle, so self-satisfied that the dip in the pavement was created just for it to exist in 🙂 [Previous page](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849.md?page=1) [Next page](https://boards.straightdope.com/t/gregorian-vs-julian-calendar-for-dummies/345849.md?page=3)