A century is one interval the time 100 years in length. When technically a century have the right to refer come any period of 100 years, most often civilization use the word century in recommendation to a certain century. These details centuries begin at a date based upon the Gregorian calendar, start with the very first century in the year 1 CE.

You are watching: How many years are in a century?

Let’s discover the different ways centuries can be defined/occur, and also how the Gregorian calendar serves as the basis for tracking the passage of centuries.

## Where go A Century Begin and End?

Photo: Geralt via Pixabay, CC0

While a century deserve to technically be any duration of 100 years, from any type of arbitrarily chosen date to a day 100 year in the future, there room two various ways that centuries are usually defined. The strict building of the Gregorian calendar defines a century together every 100 years start in the year 1 CE, therefore from 1 CE come 100 CE is the first century, and the 2nd century beginning in 101 CE and proceeds to 200 CE. The same pattern proceeds onwards, with a new century starting every 101 years. Under this strict construction, the Centennial year is the only year in ~ the century that starts with the century’s number therefore the 20th century only had actually one year v the number 20 in it – the year 2000.

On the other hand, over there is another method a century deserve to be defined. In the general, an ext colloquial intake of the term, century are characterized by subdividing them right into decades and grouping those years based turn off of their shared digits. As an example, the 21st century will be the year 2000 come 2099. The worldwide Standard for days (the ISO 8601) and the expensive year numbering system have year zeros in ~ them, and a repercussion the first century is claimed to begin with the year zero quite than in 1 CE.

The century mechanism is based on the Gregorian calendar, which is additionally the many widely supplied civil calendar in the entire world. The first century starts where that does as result of the Gregorian calendar. Let’s examine the background of the Gregorian calendar and see what different sorts of date systems and also calendars came prior to it.

## Before The Gregorian Calendar

Photo: WikiImages via Pixabay, CC0

The means our society divides time into years, days, hours and even minutes owes lot to old Egyptian civilization. The Egyptian world has its root in ancient agricultural societies that based your lives about the flooding of the Nile, i beg your pardon would occur every year. The yearly floods that the Nile helped civilization determine as soon as to grow their crops, so that was crucial to have an idea of when the floods would certainly begin. To store track that the i of years based on the yearly Nile flooding, the old Egyptian civilization invented three various calendars.

One that the calendars they followed was based upon 12 lunar months, and also each of this months began on the an initial day whereby the Crescent moon to be no much longer visible in ~ dawn in the eastern sky. A 2nd calendar, chiefly provided for the purposes of administrative tasks, was based on the increasing of the star recognized as Serpet, and it was listed at the moment that there was commonly 365 days in between the helical rising of this star. This polite year-long calendar was divided into 12 month of 30 work each, with second five job attached come the calendar in ~ the finish of the year. The 3rd calendar Egyptian society used join the polite calendar and also the lunar cycle calendar together. Attempts to revolutionary this calendar would be made, v the intention of including a leap year, however this readjust wouldn’t take place until the rule of Emperor Augustus in about 31 BCE, who let the roman Senate decree the the Egyptian calendar should have actually a leap year contained in it.

Calendars and also timekeeping would proceed to get an ext sophisticated end the following century or so, and around the year 127 CE, Hipparchus that Niceae proposed that the day need to be divvied up into 24 equal hours. Another philosopher, Claudius Ptolemeus, would later on divide those hours into 60 minute apiece. Ptolemeus would likewise create a directory of the location of the stars and also various constellations, noting down these location in an excellent detail. This star charts and tables would certainly later educate the reformation of the Julian calendar by Gregory XIII in 1582, The occasion responsible for creating the Gregorian calendar.

## The creation Of The Gregorian Calendar

Around 1572 Pope Gregory XIII was educated that the church was suffering a situation with the existing calendar system. Easter’s day of observation is based on the vernal equinox, the very first day the spring, and the passage of years on the modern-day calendar system meant that the day of Easter’s celebration to be being shifted ever before backwards. Together a result, the vacation was being celebrated too beforehand in March.

Photo: Geralt via Pixabay, CC0

At this point, the church was still utilizing the Julian calendar, the calendar initially established by Julius Caesar during his reign in the year 46 BCE, which in ~ this suggest was end 1600 year old. Caesar had made changes to the Egyptian calendar, acquisition the 365 days the the calendar was based around and making a correction come a calendar based upon 364 1/4 days, i m sorry is exceptionally close come the length of the dry year, the tropic year gift the quantity of time it takes because that the planet to revolve roughly the sun once. The calendar describe by Caesar was usually 365 job in length, but every 4 years there was an extra day included to the calendar, a leap day in a leap year.

While the calendar instituted by Caesar was quite accurate, the still wasn’t specific enough due to the fact that a complete tropical year is actually 365 days and five hours, 48 minutes, and 46 secs long. This means that the calendar instituted by Caesar was roughly 11 minutes and also 14 secs off. If this may seem like a small amount, it meant that the calendar would certainly be turn off by a full day in ~ 128 years. This errors had accumulated such the by the moment of Pope Gregory XIII, the calendar was a full 10 work off. For this reason, Pope Gregory 13 chose that the current calendar mechanism must be changed, and astronomers operated to build a new calendar that would be more accurate 보다 the Julian calendar – this new calendar being the Gregorian calendar.

The new Gregorian calendar mandated the years would continue to be 365 job long, with another day included every four years, other than there can be no leap years on year which ended in 00 – uneven that year was divisible by the number 400. Therefore while the years of 1600 and 2000 would have a leap day, the year 1700, 1800, 1900, and also 2100 wouldn’t be leap years. This brand-new calendar system was much much more accurate than the Julian calendar, in fact, present scientists only require to add a leap second every couple of years to keep the calendar aligned with the dry year.

Pope Gregory XIII mandated the the correction because that the Julian calendar it is in immediate, v 10 job taken turn off the calendar for the year. In other words, October 4, 1582, would be flourished by October 15, 1582. Pope Gregory XIII also decreed that the new year would now start ~ above January 1, whereas it had previously begun on march 25. Furthermore, the technique of determining Easter’s date would it is in changed.

As you might expect, over there was part resistance come this substantial change. Countless countries were not willing or just not all set to adjust the calendar. Furthermore, by 1582 the Catholic Church no longer had actually the authority it once had actually in Europe, thanks to the spread of Protestantism throughout the 1500s. Initially, only a grasp of countries, consisting of Portugal, France, and Italy made the readjust to the calendar. Slowly over the food of the complying with centuries, other nations would make the switch to the Gregorian calendar. In 1584, Belgium, the Netherlands, and Catholic Germany do the switch, while protestant Germany and also Denmark would make the move in 1704. Great Britain and also the colonies under its dominance would change their calendar in 1752, and also Sweden would change its calendar the complying with year. Japan ended up adopting the Gregorian calendar in 1873 as component of the westernization that occurred during the Meiji era. Egypt would adjust its calendar in 1875, and also between the years of 19 12 and 1917, Albania, Bulgaria, Latvia, Estonia, Lithuania, Turkey, and Romania would certainly all change their calendars. Greek switched to making use of the Gregorian calendar in the year 1928, and China would embrace the Gregorian calendar as late together 1949.

See more: What Level Does Rattata Evolve In Fire Red ? Rattata Line/Frlg

Many nations in the human being still have their own distinctive calendar systems that they might use in enhancement to the Gregorian calendar. Because that instance, Japan has a device of counting the years that uses particular eras or periods based on the life the the Emperor. This system is used in conjunction with the Gregorian calendar in Japan.