Grammar Bite #17: Date Formats

17 November 2011


Can you see any problems with the following date formats?

·      18 Sep 2011

·      Sep 18, 2011

·      11/10/09

·      11.10.09

·      11/10/2009

·      2003.11.09

·      Dec 24th, 2010

·      The 9th of March 2001


None of the dates are written incorrectly. But those written with numbers only can be confusing.



Most countries use this format. For example: 18 Sep 2011. Note that no comma should be used in this format.



This date format is commonly used in the US. The correct way to write it is with a comma between the day and year. For example: Sep 18, 2011.



In many Asian countries, this is the typical date format. For example: 2003 Nov 9 OR 2001.11.09 OR 2001/11/09.


The biggest problem

The main problem happens with date formats that use numbers only, especially where the year is listed as two digits (eg 11/10/09 and 11.10.09). Since the start of the 21st century, you seldom see years in 2-digit form.


But even with the 4-digit year form, using numbers to indicate both the month and day can cause problems. For example, does 11/10/2009 mean the 10th of November 2009? Or does it mean the 11th of October 2009?


Avoid confusion

We communicate across international boundaries, and it’s very important that we avoid confusion. So with date formats, always spell out the month. This can be in full form (eg, October) or in the 3-letter abbreviated form (Oct).


What about using ‘st’, ‘nd’, ‘rd’ and ‘th’?

In the last two dates above, there are small, superscribed letters: December 24th, 2010 and The 9th of March 2001. This is how you would say these dates. It’s okay to use them in written form, but it looks ‘cleaner’ if you drop the letters and simply write the day number.



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