THE BLOG
02/18/2014 12:39 pm ET Updated Apr 20, 2014

It was Valentine's Day yesterday. Can you believe it has already been two and a half months since New Years?

For those who caught the error, hats off to you.

For those still confused, only a month and a half has passed by: the month of January and half of February.

Why does this happen?

I don't have any formal scientific explanation to back me up on this but what I think is happening is we often see February 14th as 2.14 (or 2/14) but the New Years is the beginning of the year (hence 0) so our minds go straight to the conclusion that 2 months and 14 days have passed.

This is because we count from 0 not 1.

Well, when we count the number of plates on a table, we don't start by pointing at an empty space on the table and say "zero," then count "one, two, three, ...". That would just be silly.

But when we were born, we were 0 years old (although in some countries, babies are born being one year old).

When you're up until late and it's a quarter past midnight, your phone says 0:15.

When you're playing Flappy Bird and get hit on the first pipe, your score is 0.

In other words, we only count 1 when there is something rather than nothing. That is, when something has been done or something has passed.

But confusion arises when we're dealing with things like dates, months and years.

The first day of the month is 1. I haven't even spent a single day of the month but I'm already awarded 1 day.

The first month of the year is 1 (January). Next important date to remember is Valentine's Day but it's still two months away (unless you've read this post).

The first year of Anno Domini is 1 A.D., which follows 1 B.C. This makes the arithmetic so much harder.

How many years are there between 14 B.C. and 2014?

Well, the year 14 B.C. was 13 years before A.D. started but A.D. started from year 1, so only 2013 years have passed since 1 A.D. and therefore it must be 13+2013 = 2026 years. Did I do that right?

Wouldn't it be so much easier if we could line up the years on a number line and consider B.C. as just being the negative years? If we did have year 0, the years between 14 A.D. and 2014 would just be 2013 - (-14) = 2013+14 = 2027. (*2013 because the problem is principally counting the number of years from Jan. 1st of 14 A.D. and Dec. 31 of 2013)

Why did the 21st century begin in 2001?

Why are we currently in the 21st century when it's only been about 2000 years since the 1 A.D. in the first place?

It's all because of this confusion about zeroth day/month/year.

However, some cultures and civilizations did have zeroth day or zeroth year.

But even in Mathematics, there has been a long dispute on whether the set of natural numbers includes 0 or not (and still not universally settled upon).

It is conventionally thought to not contain 0 but disciplines like set theory does consider 0 to be a natural number.

Perhaps it's the translation from language to numbers that's the problem: it's only natural to name the first day of the month 1 and likewise for the months and years.
Perhaps it's because 0 appears after 9 on our keyboards (and randomly placed on our phones).

If you're interested in knowing more about 0, how it was merely an indication that the number next to it is in the higher order, or how 0 was banned in the West until relatively recently, you should definitely read the book "Zero: The Biography of a Dangerous Idea" by Charles Seife.