It's cooler to have lived from 18xx-20xx sounds like you'd have fought with Napoleon.

Our calendars are odd in general.
Concerning your thread, the way you worded it paired with the fact that I didn't bother to check when exactly she was born lead me to believe you were just being stupid. However, seeing the confusion surrounding this grey area between social-acknowledgment and "actual" calendar start-and-end points leads back to my original statement - our calendars are odd in general.

It's just a matter of convention. The Year is part of our date system and works the same as our Day and Month system. There's no 0th day or 0th month.

The first date (AD) is 01/01/0001 = 1st day of the 1st month of the 1st year of the 1st Century.

... and 31/12/0100 is the 31st day of 12th month of the 100th year of the 1st century.

... and 31/12/1900 is the last day of the 18th century

Many people think of the year as similar to their age, but this is incorrect. When you're 20 years old you are in your 21st year.

So does this mean the new millenium actually started in 2001?

Yes, based on the Gregorian calendar the 3rd millennium started in 2001.

However the popular sentiment doesn't follow the technical convention.  Popular convention refers to 1980~1989 as 80s, 1990~1999 as 90s, and 2000~2009 as rolling to the 0ties - in our popular convention 2000 is a new century and new millennium.

Basically there's no agreement here.  The 0001-based Gregorian calendar definition is correct, but people ignore it and follow the popular 0000-based convention since it's simpler, lines up with bow we now think of decades, and doesn't really make an iota of difference.

Just technicality, but I just go with 1900-1999 as 20th and 2000-2099 as 21st since it's what most people assume anyways

Ka-pi96 said: Another question: Why do people think were is spelt "where"?

Better question: why didn't the bitch teacher, "who was always correcting everyone", correct  the OP's spelling of "ridiculous" ("rediculous")?

Ka-pi96 said: Another question: Why do people think were is spelt "where"?

Well, one of the most common mistakes I see is people writing defiantly in place of definitely.