Confusing calendars
15/01/19 05:38
I’ve often written in my journal about the problems associated with the shift in calendars from the Roman or Julian calendar to the Gregorian calendar, instituted by Pope Gregory XIII in 1582. For the record, you’ll note that Gregory used Roman numerals following his name. He wrote his proclamations in Latin, too. Gregory wasn’t rejecting Roman culture. Rather, he was trying to make a calendar that was more accurate and easier to follow. The ancients notices the phases of the moon and measured the flow of time through the year by counting phase of the moon. The problem with a strictly lunar calendar, however, is that our days and years are marked by the rotation of the earth and its revolution around the sun. Observations of individual days, however, doesn’t give a calendar of seasons, and people still notices the phases of the moon that seemed to have a connection with the weather and the passing of seasons.
The Julian calendar was the product of quite a bit of experimentation. The original idea was for 12 equal months of 30 days each. The problem was that such a calendar came up short by five days. Some proposed a five day festival at the end of the year to make up the difference. Then the emperors thought that they ought to get special recognition. If julius got 31 days, so should Augustus. The competition for extra days got so intense that February ended up losing two days in the shuffle. The 365-day calendar appeared to work, but periodically, it got out of sync with the equinoxes. The Romans came up with the concept of the Ides to bring the calendar back into sync with the movements of heavenly bodies. Of course they didn’t know at the time that the earth was moving as well and so figures into the formula. The Roman terms for the phases of the moon were: Kalends, or new moon when no moon can be seen; Nones, or first quarter moon; and Ides, or full moon. When the Romans fixed the length of the moons, they also fixed the date of the Ides, so the full moon no longer lined up exactly with the Ides. In March, May, July and October, months with 31 days, the Ides was on the 15th. On the other months, the Ides was on the 13th. I’ve never learned the reason for this, but I assume it had to do with an attempt to reconcile lunar and solar calendars, though it didn’t work.
Reading calendar dates in Roman numerals took a lot of characters, especially since days were counted in terms of the number of days prior to Kalends, Nones or Ides. The day prior to one of these was called prindle. To save characters, they used appreciations. Id. was for Ides; pr. was for prindle. March 8 would be written like this: ante diem VIII Id.Mart.
If you are not already confused, look up a chart of Julian Dates on the Internet and try to find the patterns reconciling them with the Gregorian Calendar. The Gregorian Calendar, by the way didn’t work out exactly, either, thus the need to add a leap day every fourth year to the month of February. They didn’t catch this error for a while, so in 1752, officials in Britain ordered the “loss” of 11 days from the month of September and officially added a leap day to February every 4th year. Each adaptation of the calendar retained elements from the prior calendar. The names of the months come from the Roman calendar. But each introduced innovations.
As a note of trivia. the first use of the term leap day preceded the introduction of the term into the official calendar. In 1692, the first arrest warrants in the Salem witchcraft trials were dated February 29, 1692.
And, to make matters even more confusing, the calendar doesn’t even work out to whole days, so leap seconds have to be added to the timing periodically to bring the entire system into sync with the actual movements of the stars and planets.
The bottom line is that mathematics is a system of numbers that have been worked out from the imagination of generations of humans to explain observed phenomena. People wanted to count days and they wanted to be able to predict certain phenomena, such as the changing of seasons or the phases of the moon. The systematic study of mathematics and the development of formulas for figuring out mathematical problems dates back at least to the 6th century BC and the Pythagoreans. Around 300 BC Euclid introduced the axiomatic method still used in mathematics today. Modern mathematics developed in western Europe with Newton and Leibniz contributing to the concepts of calculus.
Even the most brilliant mathematician is operating within the framework laid down by centuries of thought by many different people.
The bottom line is that we all daily use concepts that took centuries to develop. Our current calendar is not perfect, but it is vastly refined from the Julian version. We didn’t get here in one generation, however. There are plenty of ideas that are bigger than oneself and bigger than the capacity of a single generation. Each generation builds upon the knowledge and concepts developed by previous generations.
The modern focus on STEM (Science Technology Engineering and Mathematics) is an acknowledgment of the need for people educated in these fields, but the concepts that are being taught are ancient. If we neglect the teaching of history in our rush to teach technical content, we run the risk of failing to pass on complete information. Like modern people navigating the quirks of the Gregorian calendar without knowing a bit of how we got to this point, we run the risk of students who are brilliant technicians yet lack an understanding of why things work or what to do when they do not work.
I continue to get on my soap box for humanities education on a fairly regular basis. Without the humanities, science becomes hollow. The future of humanity depends upon our capacity to teach and learn a broad range of subjects and ideas. In the future we’ll need to know from whence we came.
The Julian calendar was the product of quite a bit of experimentation. The original idea was for 12 equal months of 30 days each. The problem was that such a calendar came up short by five days. Some proposed a five day festival at the end of the year to make up the difference. Then the emperors thought that they ought to get special recognition. If julius got 31 days, so should Augustus. The competition for extra days got so intense that February ended up losing two days in the shuffle. The 365-day calendar appeared to work, but periodically, it got out of sync with the equinoxes. The Romans came up with the concept of the Ides to bring the calendar back into sync with the movements of heavenly bodies. Of course they didn’t know at the time that the earth was moving as well and so figures into the formula. The Roman terms for the phases of the moon were: Kalends, or new moon when no moon can be seen; Nones, or first quarter moon; and Ides, or full moon. When the Romans fixed the length of the moons, they also fixed the date of the Ides, so the full moon no longer lined up exactly with the Ides. In March, May, July and October, months with 31 days, the Ides was on the 15th. On the other months, the Ides was on the 13th. I’ve never learned the reason for this, but I assume it had to do with an attempt to reconcile lunar and solar calendars, though it didn’t work.
Reading calendar dates in Roman numerals took a lot of characters, especially since days were counted in terms of the number of days prior to Kalends, Nones or Ides. The day prior to one of these was called prindle. To save characters, they used appreciations. Id. was for Ides; pr. was for prindle. March 8 would be written like this: ante diem VIII Id.Mart.
If you are not already confused, look up a chart of Julian Dates on the Internet and try to find the patterns reconciling them with the Gregorian Calendar. The Gregorian Calendar, by the way didn’t work out exactly, either, thus the need to add a leap day every fourth year to the month of February. They didn’t catch this error for a while, so in 1752, officials in Britain ordered the “loss” of 11 days from the month of September and officially added a leap day to February every 4th year. Each adaptation of the calendar retained elements from the prior calendar. The names of the months come from the Roman calendar. But each introduced innovations.
As a note of trivia. the first use of the term leap day preceded the introduction of the term into the official calendar. In 1692, the first arrest warrants in the Salem witchcraft trials were dated February 29, 1692.
And, to make matters even more confusing, the calendar doesn’t even work out to whole days, so leap seconds have to be added to the timing periodically to bring the entire system into sync with the actual movements of the stars and planets.
The bottom line is that mathematics is a system of numbers that have been worked out from the imagination of generations of humans to explain observed phenomena. People wanted to count days and they wanted to be able to predict certain phenomena, such as the changing of seasons or the phases of the moon. The systematic study of mathematics and the development of formulas for figuring out mathematical problems dates back at least to the 6th century BC and the Pythagoreans. Around 300 BC Euclid introduced the axiomatic method still used in mathematics today. Modern mathematics developed in western Europe with Newton and Leibniz contributing to the concepts of calculus.
Even the most brilliant mathematician is operating within the framework laid down by centuries of thought by many different people.
The bottom line is that we all daily use concepts that took centuries to develop. Our current calendar is not perfect, but it is vastly refined from the Julian version. We didn’t get here in one generation, however. There are plenty of ideas that are bigger than oneself and bigger than the capacity of a single generation. Each generation builds upon the knowledge and concepts developed by previous generations.
The modern focus on STEM (Science Technology Engineering and Mathematics) is an acknowledgment of the need for people educated in these fields, but the concepts that are being taught are ancient. If we neglect the teaching of history in our rush to teach technical content, we run the risk of failing to pass on complete information. Like modern people navigating the quirks of the Gregorian calendar without knowing a bit of how we got to this point, we run the risk of students who are brilliant technicians yet lack an understanding of why things work or what to do when they do not work.
I continue to get on my soap box for humanities education on a fairly regular basis. Without the humanities, science becomes hollow. The future of humanity depends upon our capacity to teach and learn a broad range of subjects and ideas. In the future we’ll need to know from whence we came.