The year zero only exists in expressions, but not as a year. This is because the designer of the Christian calendar did not know the zero. He called the first year of Christ’s birth year one. That all sounds very simple, but the era as we now take it for granted was only developed with difficulty. The further question is whether this Christian era will remain so self-evident.
Zero was unknown
A short answer to the question of why the year 0 does not exist is: because the 0 did not exist in Christian Europe of the early Middle Ages. People knew about the existence of a 0, but philosophers could not understand that a symbol that means nothing could represent something. It had to be a diabolical invention.
In India, arithmeticians as early as the sixth century worked with 0 in the way we use it today, but they wrote it as e and space. In the ninth century, still in India, the 0 was noted as a dot and served as our 0 in the decimal system. Only in the eleventh century did this method of calculation reach Europe, via the Muslim inhabitants of Spain, the Moors. They used the dot for the zero, as they still do in Arabic today. For the record: in Arabic the 0 stands for the number five, so don’t be fooled into thinking that the Arabs invented 0. It was mainly the Italian mathematician Fibonacci (Leonardo of Pisa) who promoted this useful way of calculating in 1202.
Origin of what?
Then there is another problem with the year zero, because it suggests the beginning of something. This should be something that appeals to everyone. An era from a zero point as we know it now, with a year that has the same meaning everywhere in the world, is then not so self-evident. There are still countries and religious groups that have their own era. Devout Muslims use their own lunar calendar that begins on July 16, 622, when Muhammad emigrated from Mecca to Medina. Devout Jews use their own calendar that starts approximately one year before the creation of the earth, which is October 7, 3761 BC.
The current calendar is therefore of Christian origin. However, it was not until 526 AD that a monk Dionysius Exiguus came up with the idea of creating a calendar that started at the birth of Christ. In early Christianity this birth did not play an important role at all, which is why documentation about it was poor. In addition, most people then lived in small communities that had little contact with each other. The chronology was linked to the reign of a local monarch or a terrible event from the not so distant past. Something like that was 23 years after the war.
The Romans had a system of eras associated with consuls or emperors in power. Roman historians did use an era with a fixed origin : the founding of Rome. However, this was a mythical event whose exact date no one knew. As a result, different chronological accounts were in circulation.
Double position of Venus with Jupiter, the star of Bethlehem? / Source: BartBenjamin, Wikimedia Commons (Public domain)
The same problem arose in 526 when Dionysius came up with his calendar. No one knows exactly when Jesus was born, because the facts reported by the evangelists do not provide a clear date. In Matthew’s Gospel the king is mentioned as Herod, but he died in 4 BC. The evangelist Luke mentions the census and the Roman ruler Quirinius, which must have been in 6 AD. have been. Wise men from the east saw a special star, possibly a double position of the planets Venus and Jupiter in the western sky. It took place on February 16 in the year 2 BC. All this shows that Jesus was most likely not born in the year 1.
Christopher Clavius, a Jesuit who contributed to the revision of the calendar in 1582 / Source: Francesco Villamena, Wikimedia Commons (Public domain)
The need for central agreements
In short, year 0 does not exist and year one is not the year of Christ’s birth. An era based on this fact was not common in the early Middle Ages. Only after the first turn of the millennium did this era become increasingly used among literate people. In the centuries that followed, another problem had to be solved with leap years. Because a year is not exactly 365.25 days long, but a fraction shorter, the leap year system began to malfunction after centuries of use. The astronomically determined year was 11 minutes behind each year, in 1582 this had increased to 10 days. That is why the Vatican proposed an update of the Gregorian calendar. Catholic countries dutifully followed this advice: Thursday, October 4, 1582 was followed by Friday, October 15, 1582. But countries that had no message for the Pope, left everything as they were. England and Scotland did not adopt the new system until 200 years later, the Scandinavian countries in 1700, as did most Dutch provinces. Holland and Zeeland, although Protestant, did convert in 1582; Russia did not follow until 1918. The anniversary of the Russian October Revolution falls in November, because the old time system was used during this revolution in 1917.
Politically correct?
An era is especially valuable if it is useful for the entire world. The figure of Jesus is of course of great importance to Christianity. However, followers of this religion made up almost 30% of the world’s population in the year 2000 and this is expected to drop to 25% by 2025 (Huntington, 1997). Fortunately, the figure of Jesus as prophet and teacher is not very controversial in other religions. So there is every reason to leave the era as it is, even though we know that there are peoples such as the Chinese, the Romans and the Jews, who kept a good era much earlier. Our era is mainly based on a common agreement, just like units such as the meter for distances, the kilo for mass (weight), the ampere for electric current and the second for time. If you want to completely strip the era of its Christian origins, you speak of CE and BCE, which means Common Era (common era) and before (before) common era. I have not come across a Dutch abbreviation for this; in that case CE and BCE are used. People who think Christian Western culture is the best on earth consider the use of the terms CE and BCE to be politically correct.
The question remains whether there will be other Calendar reforms in the future. In any case, there is an organization that would like to switch to a calendar in 2012 in which the days of the week remain constant.