As the day comes to an end at midnight, the year 2019 will end, and the world will welcome the year 2020. But this time people are not just welcoming a new year, they are also welcoming a new decade. It is widely believed that the current decade began on 1st January of 2010, and will end on 31st December 2019. But although it is widely believed, not everyone accepts that, as many people say that there isa year left in the current decade, which will end on 31st December of 2020.
This is not the first time this debate is happening, this happens every time the last digit of the year changes from 9 to 0. But these debates became big after 1999-2000, as people could use chatrooms and social media on the internet, instead of just writing letters to editors. This time, digital media house Mashable has raised the bar of the debate by several notches, by declaring that if a person believes that the decade will on 31st December 2020, that person is an a$$hole.
So, when does the decade actually end? There is no definite answer to this. Whether you think it begins in 2020 or 2021 depends on what is more important for you, technically correct or convention. This fight between team zero and team one is actually a fight between mathematics and history.
If we go by the technically correct option, the decade will end after the end of the year 2020. Because, in the current Anno Domini system, there was no year 0. The current AD system was devised by a monk named Dionysius Exiguus. He had identified the birth year of Jesus Christ as 1, not 0. As a result, the calendar directly goes from 1 BC to 1 AD, there is no year zero in between.
Therefore, the first decade of the AD era should be year 1 to year 10, and the second decade began on year 11, and so on. If we believe that the current decade ends after 2019, then it means that the first decade had ended after the year 9. As that decade had started on year 1, remember there was no year 0, this means that the first decade had only 9 years, a huge mathematical anomaly. Moreover, people start learning counting numbers from 1 to 10, not 0 to 9. Therefore, it seems natural that the zero year should the last year of a decade, not first.
Therefore, the team zero has solid technical point in their side, but it is the team one that always wins. Because technicalities are not always important in day to day life, what is important is the convention in this regard. As Mashable says, technically tomatoes are fruits, but we don’t go by that scientifically correct definition, and refer to lots of fruits as vegetables, refer to lots of berries and nuts as fruits, and so on.
Historically, a decade means the year 0 to 9, like 1950 to 1959, 1980 to 1989 etc. They are called the 50s decade, the 80s decade etc. The digit in the tens place of the year determines the decade, and when it changes, the decade changes. Therefore, the 2010-2019 is one decade, the 10s, and the next decade will be 2020-2021, the 20s. Now if we want to be technically correct, we will have to rewrite lots of history that took place in zero years, as for example if something happened in 1980, they will need to be moved from the 80s decade to the 70s decade. When someone is botn in 1990, we say she was born on the 90s, not 80s. Here, 1990 is the first decade of the 90s decade.
As the term decade is used to refer to a period of ten years, it becomes less confusing when the digit in the tens place is the same. And with that convention, 2019 marks the last year of the current decade.
In conclusion, technically the decade will after the year 2020, but as per convention and common use, the decade is ending tonight itself. Just like we don’t call brinjals and cucumbers fruits just because they are botanically fruits, people ignore the science of the decades and use what is commonly used system. Here the common use wins over science.