So Yesterday was Pi Day, or was it?

David Meego - Click for blog homepageWhile working hard yesterday I came across a post shared on the Book of Face by my friend Denni Conner. It showed the mathematic constant of π (Pi) played as a song and was an interesting approach to try and memorize the sequence of numbers.

The post said it was Pi Day because the date was 3.14 and that the celebrated time was 1:59 PM as that gave the number sequence 3.14159 which is Pi to 5 decimal places and the most that “normal” people can remember. If you can remember more digits that is great, but you are in a minority.

This got me thinking as for everyone outside of the USA, the date was 14.3 and not 3.14. Disappointed I realized that we can’t have a Pi Day in Australia as it does not work, we don’t have 14 months in a year. Then I thought we could have a “Pi times 10 Day” on the date 31.4 at…. except that April does not have 31 days. 😦

You probably know that I like to tease my friends in the USA about the way they format their dates as MM/DD/YYYY. From a developer’s perspective, I can’t count how many times I have seen code that appears to work for the first twelve days of a month and generates errors from the day 13 onwards. In the Dexterity world, this problem usually comes down to writing code that contains a date variable that is passed through to SQL directly as a parameter of a stored procedure or as pass through code. The problem occurs when a date variable is converted to a string using the str() function instead of the sqlDate() function.  The str() function is affected by the current regional settings and can produce a variety of formats including DD/MM/YYYY, MM/DD/YYYY and YYYY/MM/DD.  The sqlDate() function returns YYYYMMDD which SQL Server will always interpret correctly.

So, then why does the USA use MM/DD/YYYY format when no-one else in the world does (with the exception of some countries that have been US colonies, such as the Philippines). The usual reason I hear is “Because that is how we say it and how we write it”. I know that in the USA, the date would be written or said as “March 14”. But that reason does not work, because in countries which use DD/MM/YYYY format, they say and write “14th March” or “the 14th of March”.

I accept that this is a regional difference and that no format is “right” or “wrong”. That said, I don’t understand the logic of the sequence. DD/MM/YYYY goes from smallest to largest. YYYY/MM/DD goes from largest to smallest. MM/DD/YYYY goes …. oh whatever!

I spent quite a bit of time trying to find an actual reason why the date format is different in the USA. A reason that was not “but that’s how we say it”. My favourite response to that is to ask them, what the date for US Independence Day is? The usual response is “the 4th of July”, to which I respond with a smile.

This post is not meant to be a let’s bash USA article…. I love you guys…. that, and most of my clients are in the USA. However, I really would love to know why the date format changed, when did someone change the way it was said or written from how it was said or written in other countries? If you know the reason, please comment at the bottom of the blog. I would love to hear from you.

At this stage, I am just putting it down to stubborn inertia as shown by the magenta colour (for MM/DD/YYYY) in the world map below:

Date Format by Country (source: Wikipedia)

This is just like the map for the use of the Metric System where only United States, Myanmar and Liberia don’t use it (shown as grey):

Metric System (source: Wikipedia)

Anyhow enjoy the new version of the Pi Music video:

Song from π! (with Sheet Music/HQ Download) (direct link)

Don’t forget to comment.



PS: I think everyone in the USA should celebrate Pi Day at 1:59 AM as 1:59 PM is really 13:59 if you use a 24 hour clock…. but that is another story.

This article was originally posted on


11 thoughts on “So Yesterday was Pi Day, or was it?

  1. Shall I mention miles/feet/inches? Or Fahrenheit? Or pounds/ounces? Or gallons/quarts/pints/cups/ounces? Or pounds per square inch? Or horsepower? The list of impossible to remember measurements goes on… 🙂


  2. Nice article. I would like to submit that perhaps the US follow the MM/DD/YYYY format because that is how the Fathers of the US Constitution wrote it that way and thus, we follow.


  3. Hi David. I know we’ve talk about this before and I would not be able to remember how many times I’ve seen date formats cause programming issues. Also, I have probably mentioned that I love road signs along the Canadian border which read “thinKMetric” and highlighting the KM in another color … I think that was clever by whoever came up with it.

    On another note: You missed the U.K. as a country that does not use the metric system… after all the system used by the US is called “English” for a reason.



    • Hi Thomas

      The UK is a weird case. Metric is taught in schools and not the imperial measurements. The English don’t call them “English”.

      I grew up in England till I was 13 and never learnt feet, inches, pounds and ounces. I would still have to look up the conversion factors.

      That said, the road system is still all in Miles and cars use MPH. But if you go to the shops, all the products are metric…. however, your neighbourhood corner fruit and veg shop still knows “a pound of apples”.

      It will take another generation of so before the imperial measurements start to fade away. The roads might never change as it will take years and a huge expense to change the road signs and “mile markers” on the sides of the roads.

      One final point, even in many “Metric” countries, the height of a human is still spoken about as feet and inches and the weight of a baby is often spoken about in pounds and ounces. I suspect this is for the grandparents, so they can understand.



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