This is a case-in-point exercise for the idea that man-made conventions are no universal truths, hence they need to be treated based on our own personal goals…just bear with me to make the point and be the judge of this “point of view” 🙂
Let’s take the calendar, which triggered this post. As I was preparing some posts on the New Chinese Year being celebrated at the end of next week, did a bit of research on things – should have learned this in school, I know…now I have my internet tutor 🙂 – and put together these pieces of information:
info – short version
- calendars are systems people use to organize days for social, religious, commercial or administrative purposes – basically to keep track of time , commonly defined as “the indefinite continued progress of existence and events that occur in an apparently irreversible succession from the past, through the present, into the future. This is already a man-made concept (hence, not a “truth” – just a convention that people created to keep their sanity…we keep doing this in order to create some sort of reference around which we exist. The current spacetime definition probably belongs to the same category of man-made concepts).
- people have traditionally used the sun & the moon as reference points to build their calendars on (this is what you see when you exit your cosy cavern, right?).
- people started, no one knows how & when, to use lunar calendars (they got the message the moon was sending with its influence on nature and human psychic, don’t you think?) and created their original bunch of spiritual, then religious rituals; basically in order to alleviate confusion, create social rhythms and secure political control through religious artifacts, powerful people in each historic moment created their own “reforms”
- the need to keep up with the sun’s impact eventually led to another layer of “reforms” attempting to fit 4 types of realities & needs: the two speeds at which people have to adapt to the natural world (the monthly and yearly rhythms), the social need for a common denominator (the “civil” calendar) and the human eternal need for exercising power & control (the “religious” calendar).
- On time scales of thousands of years, the Gregorian calendar falls behind the astronomical seasons. This is because the Earth’s speed of rotation is gradually slowing down, which makes each day slightly longer over time (see tidal acceleration and leap second) while the year maintains a more uniform duration. Basically physics tells us that if the giant-impact hypothesis for the origin of the Moon is correct, Regardless of the speed and tilt of Earth’s rotation before the impact, it would have experienced a day some five hours long after the impact. Tidal effects would then have slowed this rate to its modern value of 21 hrs/day (no, this has nothing to do with your feelings that the days grow shorter every day! That’s an entirely different matter, to be discussed…)
info – long version (just skip it if not interested!)
- the 1st recorded human calendar was a lunar one – the Sumerian calendar, recorded by a bunch of scribs trained by nobody know whom. But they did work with the extra month added every 4 years in order to help the lunar calendar get back in sync with the sun’s cycle and keep “seasons” in their rightful “place”. Here we go, we need people to not get confused! During this period, the first day of each month (beginning at sunset) continued to be the day when a new crescent moon was first sighted—the calendar never used a specified number of days in any month and finishes again with the last sighting of the Waning Moon. Then follows 2 days of New Moon period when no moon is visible. This system was later incorporate in all the religious systems and calendars of the literate mankind until the 5th century BC and Babilonians were the ones to celebrate every 7th day counted from the new moon, calling it a “holy-day” or an “evil-day” (meaning “unsuitable” for prohibited activities) – on these days officials were prohibited from various activities and common men were forbidden to “make a wish”, but naturally everyone was “allowed” to make offerings were to a different god and goddess. Who’d go to the temple if allowed to freely choose how to spend their time, right?
- …until basically some greek astronomer concluded (around year 430 BC) that 19 solar years equal exactly 235 lunar months and this discovery that underpins the luni-solar calendar is now called the Metonic cycle. A bunch of Hellenic calendars stem from this, and they eventually gave birth to both Roman and Hindu calendars.
- The Romans themselves described their first organized year as one with ten fixed months, each of 30 or 31 days. Such a decimal division fitted general Roman practice but fitting the natural world into a decimal system resulted in Roman dates being significantly messier and much more complicated than the earlier systems (not to mention that the system ran well short of the solar year, needing constant intercalation to keep religious festivals and other activities in their proper seasons. For superstitious reasons, such intercalation occurred within the month of February even after it was no longer considered the last month. After the establishment of the Roman Republic, years began to be dated by consulships and control over intercalation was granted to the pontifices, who eventually abused their power by lengthening years controlled by their political allies and shortening the years in their rivals’ terms of office).
- Having won his war with Pompey, Caesar used his position as Rome’s chief pontiff to enact a calendar reform in 46 bc, coincidentally making the year of his third consulship last for 446 days. In order to avoid interfering with Rome’s religious ceremonies, the reform added all its days towards the ends of months and did not adjust any nones or ides, even in months which came to have 31 days. The Julian calendar was supposed to have a single leap day on 24 February (a doubled VI Kal. Mart.) every fourth year but following Caesar’s assassination the priests figured this using inclusive counting and mistakenly added the bissextile day every three years. In order to bring the calendar back to its proper place, Augustus was obliged to suspend intercalation for one or two decades. The attested calendar of the Roman Republic was quite different. It followed Greek calendars in assuming a lunar cycle of 29 1⁄2 days and a solar year of 12 1⁄2 synodic months (368 3⁄4 days), which align every fourth year after the addition of two intercalary months. The additional two months of the year were January and February; the intercalary month was sometimes known as Mercedonius. Socially responsible people existed even then – the famous “Flavian reform” introduced by Gnaeus Flavius, a secretary (scriba) to censor App. Claudius Caecus in 304 BC consisted in of publishing the calendar in advance of the month, depriving the priests of some of their power but allowing for a more consistent calendar for official business.
- The revised calendar remained slightly longer than the solar year; by the 16th century the date of Easter had shifted so far away from the vernal equinox that Pope Gregory XIII ordered the calendar’s adjustment, resulting in the Gregorian calendar– the one we now live with in the Western world. The Gregorian calendar was decreed in 1582 by the papal bull Inter gravissimas by Pope Gregory XIII, to correct the erroneous assumption in the then-current Julian calendar that a year lasts 365.25 days, when in reality it is about 365.2422 days. Although Gregory’s reform was enacted in the most solemn of forms available to the Church, the bull had no authority beyond the Catholic Church and the Papal States. Imagine that day: Thursday, 4 October 1582, was followed by Friday, 15 October 1582, with ten days skipped! The changes he was proposing were changes to the civil calendar, over which he had no formal authority. They required adoption by the civil authorities in each country to have legal effect. The adoption of the Gregorian Calendar was an event in the modern history of most nations and societies, marking a change from their traditional (or old style) dating system to the modern (or new style) dating system that is widely used around the world today. Different countries adopted it over a span of more than 500 years!
- True enough, the Gregorian calendar mankind now generally uses as a “civil calendar” improves the approximation made by the Julian calendar by skipping three Julian leap days in every 400 years (which was introducing an error of 1 day in 128 years), giving an average year of 365.2425 mean solar days long, an approximation that introduces an error of about one day per 3,030 years with respect to the current value of the mean tropical year. However, because of the precession of the equinoxes, which is not constant, and the movement of the perihelion (which affects the Earth’s orbital speed) the error with respect to the astronomical vernal equinox is variable; using the average interval between vernal equinoxes near 2000 of 365.24237 days implies an error closer to 1 day every 7,700 years…but we have not yet seen the end of it: in the 19th century, Sir John Herschel proposed a modification to the Gregorian calendar with 969 leap days every 4000 years, instead of 970 leap days that the Gregorian calendar would insert over the same period, which would reduce the average year to 365.24225 days. Herschel’s proposal would make the year 4000, and multiples thereof, common instead of leap. While this modification has often been proposed since, it has never been officially adopted.
to the point: all of these are just points of view made by politicians who have joined hands with their religious servants in order to control the population: does the day start at midnight or dawn? / does this year start Jan.1st midnight as defined by your current time zone or Jan.25th (the Chinese New Year of the Metal Rat) or maybe Feb.24th (Losar, the Tibetan New Year – still a lunar calendar system, btw!) / should we rest Sundays or Fridays? …etc…etc
in practical terms: should we care? should we use watches built on the convention of the 24 hrs day and strive to be on time or should we spend time as our hearts urge us to? It all boils down to how well you want to blend into your environment, which boils down to how desperately you want to be accepted (basic human need!) by a certain group or by another. Really, that’s all there is! So let’s all grow up & own our decisions, shall we? 🙂