# How come we are in the 21st century if we are in the 2000s and not 2100s?

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How come we are in the 21st century if we are in the 2000s and not 2100s?

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0001-0099 is the first century. 0100-0199 is the 2nd century. etc and so on. so 2000-2099 is the 21st century.

Because our modern calendar starts with the year 1 AD. This means that the *first* century went from 1 AD to 100 AD. The *second* century was 101 – 200. Third = 201 – 300. Keep going down the line, and you see that 21st = 2001 – 2100.

1 AD to 99 AD was the 1st century so the 100s are the 2nd century and so on until 2000s which are the 21st century.

The first century went from the year 1 to the year 100, so the 2nd century was from 101 to 200, which mean the 21st century s from 2001 to 2100.

The first century CE would have been from 000-099 CE. So 0100-0199 CE would have been the second century and 1000-1099 the eleventh.

If you consider the last year of each century, it starts to become a lot more intuitive!

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1st century: year 1 to year 100 –>100:100 = 1

2nd century: year 101 to year 200 –> 200:100 = 2

20th century: year 1901 to year 2000 –> 2000/100 = 20

21st century: year 2000 to year **2100** –> 2100/100 = 21

So [0, 1) is your first year.

[0, 100) is your first century

The number marks the years that have – passed – while the term “21st century” marks the time span that is – going on currently.

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