ISO 8601 - it's time to conform

Okay people, enough individuality and freedom of choice - It's time to conform to standards.

This is a command from me, to you, on behalf of common sense.

It's time to use


ISO 8601


in our date usage.

What is the date today?

In Australia, it is 24/3/09

In the US, it is 3/24/09

According to ISO 8601, it is


2009-03-24


That is, yyyy-mm-dd.

This guy says some good stuff:

I believe that the yyyy mm dd order, going from big to small, is the natural way to write dates. My reasoning is that we almost always use a descending unit size order when we combine a number of different unit sizes of the same quantity. For example, when we write a price, we start with dollars and then go to cents, i.e. from big to small, as in $12.34.

And when you measure your kitchen for new floor covering, you measure (say) 2345 mm by 1840 mm, and then change to metres to order your material (2.345 x 1.890 = 4.432 square metres). Again, you write from big (metres) to small (millimetres). We’ve always done this. Consider the same kitchen floor using the (fortunately now obsolete) yards, feet, inches and fractions of an inch. In this case the floor would be 2 yds (big) 1 ft. 6 5/16 in. (small) by 2 yds 0 ft 2 13/32 in. I leave this calculation to others!

Indeed, our very numbering system uses the same order of big to small. Consider the number 543; the 5 hundreds (big), come before the 4 tens, and the 3 units (small) are last.

Once you adopt the numerical descending method for writing dates you make some interesting discoveries. The yyyy mm dd format:

• is preferable for sorting, filing and retrieving documents in date sequence. This is especially useful with computer files.


• makes calculations of elapsed time very much easier, especially for date calculations such as those used for the amount of interest on an investment.


• combines rationally with hh mm sss of time when you need more precision.
  

So... change your blog settings, change your calendar settings, change the way you write formal letters.

- OSO 2009-03-24 09:50:16Z

PS, for strftime, use %F %a