# How Long Is a Decade And a Century?

**URL:** <https://howtodiscuss.com/t/how-long-is-a-decade-and-a-century/49>\
**Category:** Education\
**Created:** [April 28, 2020, 9:49am UTC](https://howtodiscuss.com/t/how-long-is-a-decade-and-a-century/49 "2020-04-28T09:49:28Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![Serenity](https://howtodiscuss.com/user_avatar/howtodiscuss.com/serenity/32/4587_2.png) [@Serenity](https://howtodiscuss.com/u/Serenity)\
**Post date:** [November 24, 2020, 5:01pm UTC](https://howtodiscuss.com/t/how-long-is-a-decade-and-a-century/49/4 "2020-11-24T17:01:36Z")

</div>

## The calculation formula for the century

This is more straightforward than n = 100xn - 99. The first century spans from January 1, 1 to December 31, 100, whereas the second century spans from 101 to 200.

The 21st century spans from January 1, 2001, to December 31, 2100. 2020 is a product of the 21st century.

## The calculation formula for the decade

A decade begins with a year with the final zero and ends with a year with the last nine, such as the 1980s of the 20th century. 1980-1989 and 2020 represent the twentieth century of the twenty-first.

According to a second theory, a decade begins with the year with the final number 1 and ends with the last number 0. For instance, the tenth decade of the nineteenth century began in 2011 and will end in 2020, making 2020 the final year of this decade.

Obviously, the computation of 2020 as the beginning of a new decade or the end of a decade has little impact on life. Also, it depends on the calculations of each individual.

---

_[View the full topic](https://howtodiscuss.com/t/how-long-is-a-decade-and-a-century/49)._