Date and Time Format – Standardization – Revisit

January 1, 2019

Today is the first day of the year 2019.  I have to get used to indicating 2019 now in my date recording.  Especially, on the first month of a new year, I usually carry over the past year in my date recording.  A potential glitch that I have to be vigilant on.

While thinking of this challenge, I thought of revisiting what I wrote in 2013 regarding standardization of date and time notation format.  [see links below.]  Up to the present, 2019, I still see a lot of people and countries not using the standardized date and time notation format as recommended by ISO 8601.

Old habits die hard.  As an educator, I just have to be perseverent in reminding everybody of the standardized notation format of date and time as recommended by ISO 8601.  We live in an age of globalization. We should have a common date and time notation format to facilitate international, national, and institutional communication and to avoid misunderstanding which may lead to hitches in quality and safe services (particularly in the field of medical services – my profession).  It helps cut out the uncertainty and confusion when communicating internationally, nationally, and locally in institutions.

The standardized format for DATE as recommended by ISO 8601:



2008-09-15  – means September 15, 2008

2019-01-01 – means January 1, 2019

2019-01-11 – means January 11, 2019 and not to November 1, 2019


The standardized format for TIME as recommended by ISO 8601:

hh:mm:ss or just hh:mm


15:53:00 – means 3 o’clock in the afternoon and 53 minutes

01:01:00 – means 1 o’clock in the morning and 1 minute

12:30 – means 12 0’clock noon and 30 minutes

24:00 – means midnight

24:10 – 10 minutes past midnight


Texts from ROJoson (2013 posts):

What is ISO 8601?

ISO 8601 describes an internationally accepted way to represent dates and times using numbers.


When dates are represented with numbers they can be interpreted in different ways. For example, 01/05/12 could mean January 5, 2012, or May 1, 2012. On an individual level this uncertainty can be very frustrating, in a business context it can be very expensive. Organizing meetings and deliveries, writing contracts and buying airplane tickets can be very difficult when the date is unclear.

ISO 8601 tackles this uncertainty by setting out an internationally agreed way to represent dates:


For example, September 27, 2012 is represented as 2012-09-27.

ROJoson’s Recommendation (2013-07-03):

From now on, if you want to indicate dates with number, use the YYYY-MM-DD format.



ISO 8601 uses the 24-hour clock system. The basic format is [hh][mm][ss] and the extended format is [hh]:[mm]:[ss].

  • [hh] refers to a zero-padded hour between 00 and 24 (where 24 is only used to notate midnight at the end of a calendar day).
  • [mm] refers to a zero-padded minute between 00 and 59.
  • [ss] refers to a zero-padded second between 00 and 60 (where 60 is only used to notate an added leap second).

So a time might appear as either “134730” in the basic format or “13:47:30” in the extended format.

Or 1330 and 13:30 without the seconds.

ROJoson’s Recommendations (2013-07-03):

From now on, if you want to indicate dates with number, use the YYYY-MM-DD format.

For time, [hh][mm][ss] or [hh]:[mm]:[ss] or [hh][mm] or [hh]:[mm].


In my blogs and in my Facebook, whenever I put a date notation, I use the ISO 8601 format.  Examples: 19jan1; 18dec30; etc.

In creating a file name for my digital documents, I usually put a date notation.  Again, I use the ISO 8601 format.  Examples: roj_cv_roj_18dec31; art_assisting_opn_18nov3; etc.


This entry was posted in Date and Time Format - ISO. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s