Really mundane question about date formats (vote in post 12)

So, I’ve always known that in the US, you write month-day, just to confuse the rest of the world. But now we’re having date formats on MPSIMS breaking news, I notice they’re listed as year-month-day. Has this always been the way in the US? Must confess it makes my brain hurt trying to work out the dates on these posts.

I think it’s not commonly used but as a purely numeric format it’s the most unambiguous.

Personally I think NN LLL YYYY, e.g “17 May 2022” would be just as short and clear and look much better.

It’s the order that my brain struggles with. I’d typically write 17.05.22 (or 17/05/22). Knowing that the US puts month before day means I’m always double-taking dates to make sure I’ve read it right. Putting the year before that as well makes it doubly harder for me to decifer for some reason.

I’m a recently retired programmer; ccyy-mm-dd is the date format that can be sorted. It is probably un-American to use it. :slight_smile:

US standard is mm/dd/yy which is often confusing.

As mentioned, the ddMONccyy is a very clear format also.

This would be my vote: it’s short, unambiguous and easy to quickly comprehend.

I’m American-born and have been living and working in Europe for several years, specifically in the fintech sector for the investment industry.

When I am communicating with technical people, I write ccyy-mm-dd as it is the least ambiguous syntax, and they parse it automatically as it’s a technical standard. I therefore have no issues reading the dates as they’re being added to breaking-news titles.

When I am communicating with business people, I use dd-MON-ccyy (or sometimes dd-MON-yy) because it is the second-least-ambiguous format, and because they are not used to reading the technical date standard.

When someone else writes something like 03/05/2002, I have to ask myself: Are they following the European convention, and I should interpret it as 3-May? Or are they trying to be courteous, knowing I’m originally American, and adapting their practice to intend 5-March? It’s usually the former, but the latter is not unknown.

So in my own communication I eliminate the possibility of confusion and use the actual month name.

YMMV, FWIW, etc.

I’m prior military so I still use day/month/year (i.e., 17 May 2022)

I use that format as well. Started doing it in filenames because it got good results when sorting by filename, and now I just use it anytime I’m writing a date, even by hand.

I changed in my private sorting (own computer) to CCyy-mm-dd a couple of months ago as somebody in this board convinced me that this is the way to automatically sort correctly.
When dealing with other people I usually go for dd-Month-(CC)yy, Month written out with at least three letters (Jan., Feb., March, April, Mai, June, July, Aug., Sept., Oct., Nov., Dec.) to avoid all ambiguity. When other people write to me I always hope that the day is bigger than 12. That only works around 60% of the time.

Our Clevertouch devices are sold internationally, so the default time setting on the home screen is that used in Europe and other places. Since it is, of course, wrong, we changed them all to month-day-year. By the way, we pride ourselves in being the only country left on the planet that doesn’t use the metric system. LOL

Largest to smallest unit is The Official Standard (e.g., 2022-05-17) both inside and outside the US, but I cannot say that I use it consistently in my own notes. (If you write out the name of the month or use Roman numerals or change the order you are not conforming to the ISO standard. That is more important for computer applications.)

Here Benjamin Franklin writes “April 5, 1744”

This one by Pepys says “2-Oct-1685”
https://vll-minos.bl.uk/onlinegallery/features/images/pepys-letter.jpg
but this one says “Dec. 26. 1693.”

so I am about as consistent as Pepys, personally

I use ccyy-mm-dd for almost everything, i suppose because that sorts neatly, and i often want to files sorted. But the dates in MPSIMS aren’t going to be used for sorting, they are for people to read. I could switch to dd-mmm-ccyy (eg, 17-May-2022) if posters prefer that.

Let’s try a quick poll. If you pick “something else” please also post your preference.

  • 2022-05-17
  • 17-May-2022
  • Something else

0 voters

Oh, and if you prefer one of those but with some other punctuation, or no punctuation, vote for the one that’s in the order you like. Let’s keep comments on punctuation separate.

(Also, no promises about paying attention to what punctuation y’all like. It’s just not that important. :wink:)

I date everyone as yyyy-mm-dd but the standard here in the US is mm-dd-yyyy. I lived in Hungary for five years, where the first order is standard, but I had been using it before for file naming and sorting. Plus, logically, it makes the most sense to me to go from biggest to smallest, getting more and more specific as you read it.

I veto mm-dd-ccyy. That’s ambiguous. While the majority of our posters live in the US, we get a lot of non-us posters and i don’t want to mess them up.

I personally find ccyy-mm-dd annoying, especially with braces (sorry WE?). I prefer dd-mmm-ccyy using the 3 letter abbreviation for the month, like 17-APR-2022 for last month, for example.

I’m fine with that format. ddmmmccyy is a good format with or without the dashes. Very readable and very clear what the date is.

mmddyy and ddmmyy are the worst formats I can think of. yymmdd isn’t much better.



I got very use to ccyy-mm-dd as I was effectively on the frontlines of the Y2K projects. Once we converted to this format, it made programming a lot easier. It helped add data integrity to databases. It stuck with me. Working on other databases that still stored in older shitty formats, always bothered the hell out of me and left me looking down on a company that could be using such shitty formats in the 20-teens.

All that said, if I am still writing quickly, the mm/dd/yy format sometimes sneaks out. What we get use to as a kid is often hard to shake.

It’s ambiguous if you leave them as numbers. When using mm-dd-yyyy or dd-mm-yyyy, I always either write out the month or use an abbreviation (or use Roman numerals for the month, as Hungarians often do. But not everyone would be aware of that convention.)

PS… why are we doing ccyy (this is the first I’ve ever seen it) and adding an extra letter? yyyy should be sufficient, as the year is all four digits of the year. Is “cc” supposed to stand for century? But we’re in the 21st century.

I didn’t touch those. But I do tend to keep versions of computer files, or monthly iterations of data I need, and ccyy-mm-dd is an easy, lazy way to version stuff and have it sort neatly. So that’s my default. I can’t remember the last time I used (or saw, for that matter) dd-mmm-ccyy. But it’s a perfectly okay format for humans to read, and I’m fine using it if that’s the majority preference.

In English, the written abbreviations for months are three letters. That’s why we are writing “mmm”. That may not be obvious to everyone, thanks for highlighting that.

I was just copying WE?. But I think the meaning is clear either way.

I write ccyy-mm-dd as that is how I learned it in the 1990s. yyyy-mm-dd is the same thing of course. I think in the 90s they were trying to emphasize how important it was to move up to a 8 digit date from the standard 6 digit ones.

For our purposes I think either of these formats should be very clear. I’m good with either.

2022-05-17 or 17May2022
2012-12-12 or 12Dec2012
1995-07-22 or 22Jul1995

ISO uses yyyy-mm-dd, so that might be the closest to a “correct” format and representation of it for data at least.



Here are the supported IBM standards.

Format name Date-format parameter Date format and separator Field length Example
Job default *JOB
Month/Day/Year *MDY mm/dd/yy 8 06/21/90
Day/Month/Year *DMY dd/mm/yy 8 21/06/90
Year/Month/Day *YMD yy/mm/dd 8 90/06/21
Julian *JUL yy/ddd 6 90/172
International Standards Organization *ISO yyyy-mm-dd 10 1990-06-21
IBM® USA Standard *USA mm/dd/yyyy 10 06/21/1990
IBM European Standard *EUR dd.mm.yyyy 10 21.06.1990
Japanese Industrial Standard Christian Era *JIS yyyy-mm-dd 10 1990-06-21