1179: ISO 8601

2013-03-11T07:57:27Z

183.180.154.63: /* Explanation */ Added that YYYY.MM.DD is used in Japan (This is true when using either Gregorian years or Japanese "nengo" years) ~~BillP

{{comic
| number = 1179
| date = February 27, 2013
| title = ISO 8601
| image = iso_8601.png
| titletext = ISO 8601 was published on 06/05/88 and most recently amended on 12/01/04.
}}

==Explanation==
{{w|Public service announcement}}: Two commonly used date formats are {{w|Date format by country|dd.mm.yyyy and mm/dd/yyyy}} (the symbols separating the values, as well as the year being 2 or 4 digits notwithstanding). These differences are often causes for debate. However, the comic explains that the {{w|International Organization for Standardization}} (ISO) has standardized dates in the yyyy-mm-dd format, in its {{w|ISO 8601}} standard.

The comic then lists many formats as "discouraged". This list starts with commonly used formats, which include the two above as well as other commonly used ones, such as dd/mm/yy. However the list then starts listing formats ranging from uncommon to absurd, such as writing the date partly in Roman numerals and painting the date in m-d-yy format with white paint onto a hissing black cat.

The ISO standard was published (to use yet another date format) on 5 June 1988 and amended on 1 December 2004, two dates given in the title text in mm/dd/yy format. Since the day values are less than 13, the format used demonstrates its ambiguity; it could be interpreted as other dates given in dd/mm/yy format (the last in several other formats as well). Anyway, the dates are not written in ISO 8601 format, contradicting the advice in this comic, adding a level of metahumor.

The other mentioned formats are:

{| class=wikitable
! Date !! Explanation
|-
| 02/27/2013
| MM/DD/YYYY, used mostly in the US.
|-
| 02/27/13
| MM/DD/YY
|-
| 27/02/2013
| DD/MM/YYYY, used e.g. in South America, Canada ({{w|Date_and_time_notation_in_Canada|officially uses ISO 8601}}) and Europe.
|-
| 27/02/13
| DD/MM/YY
|-
| 20130227
| YYYYMMDD, also allowed in ISO 8601
|-
| 2013.02.27
| YYYY.MM.DD, used in Japan
|-
| 27.02.13
| DD.MM.YY, used e.g. in Germany
|-
| 27-02-13
| DD-MM-YY, used in Denmark, Netherlands, Indonesia, India, Bangladesh, etc.
|-
| 27.2.13
| D.M.YY
|-
| 2013. II. 27.
| YYYY. MM. DD., with month as {{w|Roman numerals}}, used in Hungary.
|-
| 27⁄2-13
| D⁄M-YY
|-
| 2013.158904109
| Year and decimal fraction of year – 58/365, February 27 being the 58th day of the year. This representation marks the end of that day. Also allowed in ISO 8601.
|-
| MMXIII-II-XXVII
| Year-month-day in Roman numerals
|-
| MMXIII [and] LVII [over] CCCLXV
| Year and ''57''/365. This representation marks the start of the day, which is 57 days after the year started.
|-
| 1330300800
| {{w|Unix time|UNIX Timestamp}}, but for '''2012'''-02-27.
|-
| ((3+3)×(111+1)-1)×3/3-1/33
| Year/month/day with the parts written as arithmetic expressions, using just the digits 1 and 3. (The slashes are not to be interpreted as fraction lines.)
|-
| 27 [''on''] 02 [''on''] 2013
| An obfuscated date format not used ordinarily. This can be considered a compromise between the different formats: since we cannot agree on which position in the date the day, month and year parts shall be, we just write them all in the same place; we don't even need separators, which we cannot agree on either. On the other hand, reading it gets somewhat tricky...
|-
| 10/11011/1101
| Month/day/year in {{w|Binary number|binary}}.
|-
| 02/27/20/13
| A slash is absurdly placed in the middle of "2013".
|-
| 0 [2,5] 1 [3] 2 [1,6,7] 3 [4] 7 [8]
| The large digits are to be placed at the positions listed above and below: 0 is used at positions 2 and 5, 1 is used on position 3, etc.; the result being 20130227
|-
| ''A cat with'' "2-27-13" ''painted on it, going'' HiSSSS
| In Western cultures, black cats and the number 13 are associated with bad luck. The cat might also just be angry that someone painted an (unstandardized) date on it.
|}

==Transcript==
:Public Service Announcement:

:Our different ways of writing dates as numbers can lead to online confusion. That's why in 1988 ISO set a global standard numeric date format. This is '''''the''''' correct way to write numeric dates:

:2013-02-27

:The following formats are therefore discouraged:
*02/27/2013
*02/27/13
*27/02/2013
*27/02/13
*20130227
*2013.02.27
*27.02.13
*27-02-13
*27.2.13
*2013. II. 27.
*27⁄2-13
*2013.158904109
*MMXIII-II-XXVII
*MMXIII [and] LVII [over] CCCLXV
*1330300800
*((3+3)×(111+1)-1)×3/3-1/33
*27 [''written on top of''] 02 [''written on top of''] 2013
*10/11011/1101
*02/27/20/13
*0 [2,5] 1 [3] 2 [1,6,7] 3 [4] 7 [8]
*''A cat, with the numerals'' 2-27-13 ''painted on it, going'' HISSSS

{{comic discussion}}

[[Category:Math]]

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1179: ISO 8601