Annoying Date Formats

Randolph West shows that even The Best Date Format can deceive you under certain circumstances:

Look carefully. DATE and DATETIME2 are showing the date of 12 July 2017 as expected. Unfortunately, the DATETIME and SMALLDATETIME data types are showing a date of 7 December 2017.

That’s not good at all. It means that the ISO 8601 standard does not work the way we might expect it to. The reason is simple, if annoying: we need to add a time to the date to make it pass the ISO 8601 standard.

I don’t like the idea of having to write 20170713 instead of 2017-07-13, but that is the only date format in SQL Server that I’ve run across that will work with any language and culture settings.

Related Posts

Using DATEADD Instead Of DATEDIFF

Michael J. Swart points out a bit of trickery with DATEDIFF: I assumed that the DATEDIFF function I wrote worked this way: Subtract the two dates to get a timespan value and then return the number of seconds (rounded somehow) in that timespan. But that’s not how it works. The docs for DATEDIFF say: “Returns the count (signed integer) of […]

Read More

When AT TIME ZONE Is Too Slow

Robert Davis troubleshoots a performance problem relating to time zones: Time Zones were definitely being a drag today. I got an email from one of the developers at work asking about the performance difference between 2 queries. The only difference between the 2 queries is that one of them uses the AT TIME ZONE clause that was […]

Read More

2 Comments

  • John Spencer on 2017-07-17

    Yes, I (along with many others [I am sure], have run into this thing of ‘annoying’ date formats. The ‘tried and true for me has also been the YYYYDDMM format. And when including the time–using the 24 hour time format of HHMMSS has also been the ‘only’ way I have been able to have things work as expected.
    Yes, I have made ‘assumptions’ in the past — and have been burned. Thus, that absolutely fitting ‘annoyance’ word.

    Good article for the ‘unwary’

  • Ed Eaglehouse on 2017-07-18

    Yet another example of Microsoft’s disrespect for standards, to the detriment of its customers. The ISO-8601 standard works; Microsoft just didn’t implement it correctly, as usual.

Comments are closed

Categories

July 2017
MTWTFSS
« Jun Aug »
 12
3456789
10111213141516
17181920212223
24252627282930
31