This Rosh Hashanah I switched to the Jewish calendar full-time. I know this may sound impractical (it is) but it has always felt like an important issue to me as a mostly secular Jewish American. In my opinion the Gregorian calendar offers very little advantage (perhaps even disadvantage) over lunar-solar alternatives. Its popularity has been deeply tied to Christian imperialism and its adoption has often been forced. The Gregorian calendar is technically more accurate as it is off by 27 sec/year (1 day in 3236 years) compared to the Jewish calendar which is off by 7 min/year (1 day in 216 years). This, however, has always felt to me like comparing apples to oranges. The accuracy of the Gregorian calendar comes at the expense of functionality (lunar calculations) which I find to be incredibly useful. With the Jewish calendar you always know what phase the moon is in as the start of each month is a new moon and the middle is a full moon. Not only does this have real-world application in terms of tides, agricultural conditions, night light, animal behaviors, and etc but I have found myself feeling more mindful of nature as a result. It still trips me out that I can go outside and know exactly what the moon is going to look like without googling it! Furthermore, days ending at sundown makes so much more sense to me! There is a certain satisfaction that comes with watching the sunset and it marking the end of your day compared to the day ending in the middle of the night while you are asleep. Lastly, I have felt myself feeling far more connected to my culture as I am more aware of holidays and other traditions that were lost when the Gregorian calendar took over.
On my android phone I used KLCK and KWGT with the hebcal RSS feed above to create a lockscreen and homescreen Jewish calendar widget. On my laptop I run Sway+Waybar and created a custom waybar module with libhdate. It's not perfect but it's working for now!
>Its popularity has been deeply tied to Christian imperialism
Well, Roman Imperialism. The sheer reach of the Roman Empire is the reason why it became a de facto standard, difficult to displace. The month names are still Roman, and the days of the week are pagan gods.
I like learning about these historical time reckoning methods. Using the solar system as a clock is a nice way to be more in touch with the cosmos. I’m still fond of our new gps time though. A simple number line that doesn’t skip a beat and clocks so accurate that I can get a feel for the warping of spacetime.
> The difference is that GPS time is not corrected to match the rotation of the Earth, so it does not contain leap seconds or other corrections that are periodically added to UTC.
Roman Imperialism that was peddling Christian Imperialism. Let us not forget that the calendar was made for and named after Pope Gregory XIII and the years are structured around the death of Christ. Naming the weeks after pagan gods (in my opinion) was a similar act to moving Christmas to fall on Saturnalia. The purpose being to appease pagans and slowly convert them to Christianity.
The Gregorian calendar was a relatively light modification to the Julian Calendar, created by Julius Ceasar, who predates both Christian Rome and Christianity as a whole. The Gregorian calendar is very much a Roman calendar, with a slight astronomically-inclined update by Gregory to fix leap year drift, 1500 years after Caesar introduced it.
That the years are structured around the death of Christ... Eh? Hard to say. I believe that was retro-fitted, and probably was more centered around Augustus's rise to power and Rome moving from a republic to an empire. Or maybe not, I haven't read the relevant wikipedia page for that.
While the Julian calendar was clearly more secular, The motivation for the adjustments in the Gregorian calendar was to re-align Easter to a historically accurate date and to ensure that people around the world were celebrating it at the same time. While you are definitely right that the Gregorian calendar stems from Roman culture, one cannot deny that its revisions were religiously motivated and funded. Further, that its history and global adoption is intertwined with the spread of Christianity around the world. With its global adoption cultures all around the world have lost their connection to their own calendars and practices. As for the BC/AC part I believe it was always part of the Gregorian calendar? The Julian calendar also used BC/AC. :)
EDIT: I meant to say that the Julian calendar did not always use BC/AC but adopted it some time prior to the invention of the Gregorian calendar.
> While the Julian calendar was clearly more secular, The motivation for the adjustments in the Gregorian calendar was to re-align Easter to a historically accurate date was in the focus results not only from the fact of it being the most important festival, but from the complexity of its calculation
The motivation was to stop the drift of the whole Christian festival calendar towards later and later days in the year. We have some confusion about Easter in contemporary accounts of the reform, but the date of Easter when calculated as the first Sunday after the first full moon after the spring equinox is independant of any calendar system. This would have implied that all other festivals, based on the Julian Calendar, would have caught up and then overtaken Easter (and caught up again, etc.).
> and to ensure that people around the world were celebrating it at the same time.
This was definitely not the intention. All people in the Protestant/Catholic/Orthodox "realm" were already using uniformely the Julian Calendar. Differences of the Easter date were due to different algorithms for its calculation. In practice, on the contrary, it led to more differences, because the reform was not accepted for a long time in many parts of the Christian world, even in Catholic ones.
> While you are definitely right that the Gregorian calendar stems from Roman culture, one cannot deny that its revisions were religiously motivated and funded.
Well, the flaws of the Julian System had a consequence for the Christian festival calendar. But to correct this flaw was also a very reasonable thing to attempt. We are in in age were astronomy (and astrology) become a very popular science.
> Further, that its history and global adoption is intertwined with the spread of Christianity around the world.
This is not true. For example in what become later the British empire the Julian Calendar was in use until 1752. So for many areas the adoption come long after Christianity took roots. And then it was implemented in areas that never become widely Christian, such as India.
> With its global adoption cultures all around the world have lost their connection to their own calendars and practices.
Most did not loose connection. It become rather dual use.
> As for the BC/AC part I believe it was always part of the Gregorian calendar? The Julian calendar also used BC/AC. :)
> EDIT: I meant to say that the Julian calendar did not always use BC/AC but adopted it some time prior to the invention of the Gregorian calendar.
"BC/AC" is wrong, it is: "BC/AD" ("Before Christ" and "Anno Domine" = "In the year of the Lord").
The Gregorian Calendar strictly speaking applies only to dates after AD 1583. If you extent it backwards (avoiding the date gap in 1583), it is called the "proleptic Gregorian Calendar". There exist different version of it. For example ISO 8601 uses a proleptic Gregorian Calender with a year zero.
Besides first appearances in the late 15th century, Julian Calendar BC dates started to be widely used only much later than the Gregorian reforms. When writing about ancient history, authors used AUC dates ("Ab urbe condita" = "From the founding of the City [Rome]" = 753 BC) or dated from the (suppost) beginning of the world, thus avoiding negative numbers.
Julius Caesar created the Julian calendar as part of his role as Pontifex Maximus. Popes continue to hold that title today, so the Pope updating the calendar is weirdly appropriate.
(For context I'm not Christian I'm Muslim) Wait is the modern pope an extension of the Christian Roman emperor? I always knew the Vatican was in Rome, but I never knew the reasoning
In some sense, the Roman Catholic Church is the last vestige of the Roman empire. The Pope is sometimes floated as someone who might have a claim to the title of Roman Emperor. (Personally, I think the Ottomans have the best claim here, but that's neither here nor there.) But no, at the time Julius Caesar was Pontifex Maximus, he wasn't emperor. It was an elite priesthood office. Hundreds of years later, the Roman Emperors claimed the title. In the 15th century, the Roman Pope started formally claiming it for themselves.
There is no right or wrong since nobody actually knows when Jesus was born. The Bible is inconsistent regarding the birth of Jesus, so the calendar had to make a choice.
Well, there is a correct answer that might be an unknown. If you compare the named rulers death dates with the New Testament there is a very obvious error.
It is true that Christians integrated some pagan holidays (and in the process Christianity became more Germanicized). Around the millennium.
But much before that, Jewish-Christians were not exactly friendly to Romans/"pagans", and vice versa. To put it lightly. Clash of civilizations: completely different values.
The appropriation of pagan holidays by Christianity is a myth, originally pushed by Protestants to discredit extra-biblical Catholic traditions but later uncritically accepted by atheist activists who didn't know any better.
> Its popularity has been deeply tied to Christian imperialism and its adoption has often been forced.
I am sorry to be the bearer of bad news but ancient Israel was also a kingdom/empire.
You are just migrating from the conventions from empire to the conventions from another one.
If imperialism is bad there might be non-imperial calendar alternatives you may enjoy more, like the French Republican calendar.
If you dislike Ancient Rome, you may also consider not using the Latin alphabet.
Most of the atrocities you mention took place during a time when literacy rate was really low, masses took place in Latin and absolutely nobody understood what was going on. Copies of the Bible were extremely expensive and for over 1000 years there was not even paper to print them. Most of the people involved in those acts of violence had no idea what actual Christianity even meant because their only connection to Christianity was attending a church on Sunday where the entire thing was in Latin.
Jesus was an extremely tolerant guy and his message was one of tolerance and forgiveness, which is extremely unusual for a monotheistic belief system.
Another thing to take into consideration is that it is the successor of Christian imperialism mostly what helped found modern Israel and is helping protect Israel today. So perhaps it may be a good idea to relax those views a bit.
This is getting a bit out of the scope of HN but... here goes nothing. Firstly, Jews =/= Israel! I have never been to Israel and do not plan on ever going. Nor do I support their actions/government. Secondly, the United States and other governments do not protect Israel for Christian fundamentalist reasons. While republicans would like you to believe they support Israel so that Jesus can return to Earth or whatever shit they believe the truth is that they are simply preserving hegemony in an oil rich region that lines their owners pockets. Second of all, Christian imperialism is clearly a much bigger concept than Roman imperialism. Countless nations have utilized Christian fundamentalism as a excuse to colonize people all over the world and commit atrocities. Yes the romans spread the gregorian calendar but it was created for and named after Pope Gregory XIII. The calendar clearly has far more to do with Christianity than the Roman empire. I mean the entire thing is built around the death of Christ. None of this is to say that Jews have not committed sins or carried out horrible acts in the name of their religion, however, unlike most religions proselytizing is a feature (not a bug) of Christianity. The Gregorian calendar has clearly been used as a tool to achieve this goal. Lastly, I aim to look forward and not backwards in life. We cannot change the past but we can question our present structures and hierarchies. By switching to the Jewish calendar I do not aim to convert others to Judaism, I simply am trying to reconnect to my all too often forgotten roots.
The Gregorian calendar is a bugfix on the Julian ones though, and while julius Caesar might have been pope, but definitely not Christian. He's 100% the roman empire guy though
"Pope" comes from the Latin Pontifex Maximus". Julius Caesar (100 - 44 BCE) was a Roman Pontifex Maximus, Gregory VIII (1572 - 1585 CE was a Catholic Pontifex Maximus.
And keeping track of calendars was part of their job!!
>The Pontifices were in charge of the Roman calendar and determined when intercalary months needed to be added to synchronize the calendar to the seasons. Since the Pontifices were often politicians, and because a Roman magistrate's term of office corresponded with a calendar year, this power was prone to abuse: a Pontifex could lengthen a year in which he or one of his political allies was in office, or refuse to lengthen one in which his opponents were in power. A Pontifex with other political responsibilities, especially away from Rome, might also have been simply distracted from his calendrical duties as chief priest. This caused the calendar to become out of step with the seasons; for example, Caesar's crossing of the Rubicon in January 49 BC actually took place in mid-autumn.
Under his authority as pontifex maximus, Julius Caesar introduced the calendar reform that created the Julian calendar, with a fault of less than a day per century, and which remained the standard till the Gregorian reform in the 16th century.
While the Julian calendar was clearly more secular, The motivation for the adjustments in the Gregorian calendar was to re-align Easter to a historically accurate date and to ensure that people around the world were celebrating it at the same time. While you are definitely right that the Gregorian calendar stems from Roman culture, one cannot deny that its revisions were religiously motivated and funded. Further, that its history and global adoption is intertwined with the spread of Christianity around the world. With its global adoption cultures all around the world have lost their connection to their own calendars and practices.
D'varim 13 demands that Israeli(te) cities practice Judaism, but does not extend that to any other region. Proselytizing to non-Jews (historically, non-Israelis) is explicitly banned in Judaism.
Heh, that guy even made his way into Judaism! Since Judaism is the closest surviving descendant of the ancient Canaanite religion (and the language we call "Hebrew" is simply a Canaanite dialect, mutually intelligible with the other Canaanite dialects that have since died out). We merged him into Yahweh, the original god of Judea; others were merged in too, e.g. El's original consort Asherah became the "Shekhinah" (feminine presence of Yahweh) and also "Shabbat Ha'malka" (the vaguely-mystical but uh, totally not a deity, yup, uh-huh, figure called the "Queen of the Sabbath").
I didn’t know that the day ends at sunset. Did they also have a different clock for hours and minutes or it simply didn’t exist?
Just wondering about Jewish timezones and keeping server times if days get longer and shorter at different places based on both latitude and longitude ;-)
At least around the time of Roman rule the day was divided into what are called "canonical hours" so that there were 12 equal hours during the day and 12 equal hours during the night. This meant that during the summer the hours during day would be longer than the hours during the night and vice versa during winter.
But keeping track of the hours themselves was a bit hard, so usually people only referred to three major hours of the day: Terce, around mid-morning; Sext, at noon; and None, around mid-afternoon.
So yes, the hours of the day were absolutely dependent on the latitude (along with the day of the year).
Yes! Great intuition. The Jewish timekeeping scheme is based on "relative hours" — there are always precisely 12 hours of daylight, and 12 hours of night, regardless of how long the day or night is. The time is directly associated with the position of the sun relative to the Earth.
> more connected to my culture as I am more aware of holidays and other traditions that were lost when the Gregorian calendar took over.
Didn’t every culture basically use a lunar calendar before the Gregorian calendar? I remember reading that the oldest lunar calendar was found in Scotland or something.
Totally relate to your comments about being closer to nature when being aware of the moon cycle. It’s like we’re living in a clock and we’re using the gears to keep time instead of the hour hand.
makes me wish more of pre-Christian European culture had persisted.
The ancient Egyptians did not. They used a 365 day calendar that consisted of 12 months of 30 days plus an extra 5 days at the end. But because they didn't have any leap days, the calendar would gradually cycle through the year relative to the seasons.
The Jewish are not the only one. In fact the Indian calendars also called panchanga, have a very elaborate system tied to the luni-solar movement and get very detailed into calculation. My guru once jokingly said when he was nominated to lead his specific religious institution, I’ll only agree to head the mission if I Don’t have to deal with the calendar calculation. As there are many parameters which tend to invite debate. Here is one I use almost daily for the Vaishnavite sect I follow. (1) you’ll notice you have to select your time zone and city as some of the holy fast days (also tied to luni-solar movement called ekAdaShi) depend on the sunrise time.
Actually this month that we are entering, also known as Kartik, named after the constellation Krttika, where the moon is full, is a very holy month in the Indian calendar and contains the special Diwali festival on the amavasya or new moon night.
The 19-year metonic cycle (of the Jewish and Chinese calendars) has always struck me as clever but inconvenient - how do you quickly calculate if we'll have an extra month in x years from now? The Gregorian calendar's algorithm - every 4 years, except if divisible by 100, except if also divisible by 400 - is both clever and elegant.
Indeed Plato considered astronomy to be the highest form of knowledge. To him it was superior to plane geometry (two-dimensional mathematics) and solid geometry (three-dimensional mathematics) since it was four-dimensional mathematics --- the study of the motion of three-dimensional objects through time.
That conception was much older, probably in the early Archaic Age. By Plato's day it was believed that the planets were different distances from the Earth with the Moon being closest, Saturn being the farthest, and the sphere of the fixed stars being beyond that.
Because the moon is a big bright ball in the sky which regularly moves through predictable, easily observable phases, making it an obvious basis for a system of measuring time.
The complexities, irregularities, and imprecisions of our calendars are due to things like
* the Earth's rotational period ("day")
* the Moon's orbital period ("month")
* the Earth's orbital period ("year")
not being integer multiples of each other at all! Despite that, we naturally want to keep time in terms of each of these -- as you said, they're all such extremely noticeable periodic phenomena. According to GNU units, the day is
24 hr = 86400 s
(which is a historical basis for defining the second, though not the method we officially use now because we have clocks that are more consistent than the Earth's rotation), while the lunar month is
29 days + 12 hours + 44 minutes + 2.8 seconds = 2551442.8 s
and the tropical year is
365.242198781 day = 31556926 s
If we think of a month as a fixed whole number of days, and/or think of a year as a fixed whole number of months, and/or think of a year as fixed whole number of days, it's been known for thousands of years that we're eventually going to get in trouble astronomically and require some adjustments.
It's not so hard to know if there will be an extra month using the Metonic cycle. You just add an extra month in the 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years.
That may sound complicated to remember, but consider how we figure out how long a month is in the Gregorian calendar. There are 30 days in the 4th, 6th, 9th, and 11th months and 28 days in the 2nd month (except for leap years). At least with the old lunisolar calendar you can figure out where you are in a month just by looking at the moon.
While in synagogue on Yom Kippur a few days ago, I noticed (for the first time) that the "song of the day" in the Machzor (prayer book just for Yom Kippur) only has options for Monday, Wednesday, Thursday, and Saturday. And it made me think, how can they be so sure that Yom Kippur will never fall on a Sunday, Tuesday, or Friday? Thanks to this wonderful write-up, now I know: the Jewish calendar has a "business rule" that guarantees it!
The relation to the bug in his code at the end was interesting. It took the story in a direction that I was not expecting. Honestly, reading through the first 95% of the fine article I was wondering why this was posted to HN. The end was worth it.
The bug was foreshadowed in the beginning of the story when he said that the first year was the same as the first week.
Steve Morse should have asked Rabbi/Professor/Mathematician/Cosmologist Shlomo Sternberg, Mathematician/Cosmologist (Born 1936), for help in the 1970s or 1980s.
I highly recommend reading Calendrical Calculations, a book by Edward Reingold and Nachum Dershowitz. It is a beautiful combination of computer science and calendar systems. Also, the Hebrew calendar truly is a marvel, as the book goes through.
I had a Jewish friend who once remarked that he knew when rosh hashana and yom Kippur were upon him because it added another forty minutes to his commute in Los angeles. he affectionately called it "the ten days of 'awe come on merge already'"
Tom Lehrer wrote a song called "I'm Spending Hanukkah in Santa Monica" (https://www.youtube.com/watch?v=LslsgH3-UFU) — I had assumed it was just a joke for the rhyme, but looking at this conversation I'm wondering if there's anything more to it :)
> The Boyle Heights section of Los Angeles, located east of downtown, was home to the city's most populous Jewish community from 1910 to 1950. The area around Breed Street Shul became a center for the Jewish community.
Yeah, that's fair. I was thinking more the post-WWII population which became centered more in the Pico-Robertson neighborhood. Pre-WWII Los Angeles was very different.
Yes, adding several hundred drivers all entering/exiting at the same spot in rush hour at specific spots the 405 can do that. Thinking the one on Mulholland Drive right near the 101/405 interchange.
For anyone interested in calendars, check the proto-Bulgarian calendar.
It is considered to be one of the oldest if not the oldest, and most accurate in the world by UNESCO.
There is a website that rebuild it from the ancient documents describing it, and it is compared head to head with the Gregorian calendar, you can also find the code on github, it is cool.
Its curious that with the all day additions and removals it still doesn't correct more accurately to the drift. 1 day for 217 years might not be huge, but still feels significant, especially when considering that the julian calendars 1 day per 128 years was deemed unacceptable already back in 16th century. Although I suppose correcting might be tricky without compromising on the lunar cycle accuracy?
There is no Sanhedrin, the only body that could correct this without a schism. As for making the correction a slight mucking about with the molead rules could do it.
Pan-Jewish changes to Halakha (orthodox law) are still theoretically possible. The last significant such occurrence was the ban on polygamy in Judaism about a millennium ago. It's just a question of how many rabbis, across how many streams of Judaism, would need to reach a consensus, in order for it to be reasonable to consider an amendment as "widely accepted".
In terms of changing the calendar rules, I doubt that there would be any chance of pan-Jewish consensus for quite a few more millennia, that is, not until the dates of major festivals get significantly more out of whack than they are now.
hey, some (major) rabbis believe that sabbath in japan should be on sunday. (and others believe that in western alaskan islands, it be friday, i.e. if there's a concept of a "date line" in halacha, than the area between the international date line and the halacha date line would be offset by a day depending on which side it is).
I was born on the 30th of Cheshvan which as he explains is one of the days that doesn't show up every year (I guess is the equivalent of February 29th). I've always wondered how many birthdays I've had - does anyone know of a list of which years are chasar/maalei?
I was born right at sunset between the 29th of Cheshvan and the 1st of Kislev. It's like I was trying to be born on the 30th. It's not actually totally clear when my birthday is but I generally use 1st of Kislev. Fun fact, the year of my Bar Mitzvah there was a 30th of Cheshvan so it was something like "I turn 13 on Tuesday or Thursday, but definitely not Wednesday".
Right, that's essentially the same thing, with aleph being a shortened way of saying rishon and bet being a shortened way of saying sheni. My original point was that I'd never heard of "ve'adar". Apparently as the Wikipedia entry says, that's less common. Curious if the Mishna or Talmud ever uses "ve'adar" (I've never seen it, but doesn't mean it doesn't exist)
Would be an interesting paper to compare calendars worldwide. I am seeing many parallels between the Jewish and Hindu calendars. Ours also has an extra month thrown in every few years which is called Adhik Maas, mal maas, or purushottam. This article is quite well written and also entertaining at the same time. I enjoyed it
Emacs supports the Hebrew calendar out of the box (alongside Julian, Islamic, Chinese, Mayan, Coptic, French Revolutionary etc etc) but I've never worked out how make much use of it. Anyone have suggestions to get the festivals into Org Agenda, for example?
I remember a long time reading a text file from a package while browsing my /usr/share/docs about the history of Gregorian calendar date in the history, i think it was pretty interesting but I can't find the name of that package of where this was located, (can't seem to be in coreutils/utils-linux except if that has been removed). if anyone would know what i am talking about, i'll be grateful to know the name of the package.
Hmm, considering that the Jewish New Year ended in the middle of September that year, it actually is a question. I suppose it depends on whether that journal was actually published before or after Rosh Hashanah that year.
Some resources for those who are interested:
libhdate (Jewish date + cal alternative for Linux) https://sourceforge.net/p/libhdate/wiki/Home/
hebcal (RSS, CSV, Google/Apple/etc calendar integration) https://www.hebcal.com/
On my android phone I used KLCK and KWGT with the hebcal RSS feed above to create a lockscreen and homescreen Jewish calendar widget. On my laptop I run Sway+Waybar and created a custom waybar module with libhdate. It's not perfect but it's working for now!