How Long Is A Century?

This article was last updated on 1 October 2021.

How Long Is A Century In 2021?

This article will look at how long a century is and questions that you might have related to this.

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How long is a century?

A century is a period of time that is 100 years in length. 

The word century comes from the Latin centum, meaning one hundred. Century is sometimes abbreviated as ‘c’. 

A century can refer to any period of 100 years but in terms of how the term is used, it is usually in reference to a specific century.  The centuries that people refer to are often based on the Gregorian calendar, beginning with the first century in the year 1 CE. 

As mentioned earlier, the century system is based on the Gregorian calendar, which is the calendar that most of the western world uses. The first century begins where it does due to the Gregorian calendar .

Although a century can mean any arbitrary period of 100 years, there are two viewpoints on the nature of standard centuries. 

The first is based on the strict construction, while the other is based on the popular perspective.

According to the strict construction of the Gregorian calendar, the 1st century AD began with 1 AD and ended with 100 AD, with the same pattern continuing onward. In this model, the n-th century started in the year (100 × n) − 99 and ends in 100 × n. 

Due to this interpretation, a century will only include one year, the centennial year, that starts with the century’s number.

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When does a century start?

You can start one of two ways.  You can either start with a specified date or just from the first of Jan in the 00 year to the 31st of December in the 99 year (1900 to 1999). 

How many days in a century?

The number of days in a century differs according to the 100 year period you are booking at. 

The 21st century is 36,503 days, whilst the 20th was 36,504 days. The difference is because of how the Greogorian calendar works.

What is a centenary?

A centenary is a hundredth anniversary, or a celebration of this.

This would typically be the remembrance of a specific historical event, which as the name suggests, would have taken place a hundred years earlier.  

Where Does A Century Begin And End?

While a century can technically be any period of 100 years, from any arbitrarily chosen period in time, there are two ways that the term century is constructed.  

As mentioned above, with the strict construction of the Gregorian calendar, this defines a century as every 100 years beginning in the year 1 CE, so from 1 CE to 100 CE is the first century, and the second century starts in 101 CE and proceeds to 200 CE. 

This interpretation continues onwards, with a new century starting every 101 years. Under this interpretation, the Centennial year is the only year within the century that begins with that century’s number.

How long is a century and a quarter?

A century and a quarter is a period of 125 years.

How long is a century in decades?

A decade is measured as a period of 10 ‘years’.  A century is measured as a period of 100 ‘years’. Therefore,  there are 10 decades in a century.

How long is a century in seconds?

This answer to this will depend on which century you are looking at, depending on how many leap years there are in that century.

Three out of every four Centuries have 36,524 days each, while the other Century has an extra leap year so has 36,525 days.

Therefore, based on 36,524 days, there are 3,155,673,600 seconds

Based on 36,525 days there are 3,155,760,000 seconds.

How long is 50 years called?

There are a number of terms you can use including semi century, half a century or semi centennial.

What is a 1000 years called?

A time span of 1,000 years is called a millennia or a millennium.

What’s bigger than millennia?

Beyond millennia, terms you can use include a Galactic Year, or sometimes called a cosmic year.  

A galactic year is in the region of 230 million years. 

It is also known as a Cosmic year, as this is the number of years required for the solar system to orbit around the center of the Milky Way galaxy.

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Sarah Taylor

Hi, I am Sarah and I am the primary author for this website.  I’ve always been interested in useless and quirky facts and that led me to create this website.

My aim here is to focus on questions related to ‘How long….”.  My mission is to make my little site the go-to site for anyone that has a question they want answering.

Outside of this site, I love baking and making marmalade and jams.  It is something I have dine since I was a child and something I love doing with my little girls 🙂

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