ISO 8601
ISO 8601 was published on 06/05/88 and most recently amended on 12/01/04.
ISO 8601 was published on 06/05/88 and most recently amended on 12/01/04.
When abbreviating the date into numerical form, various areas of the world tend to list the year, month, and day in different orders (as well as with different delimiting symbols), which can cause confusion particularly when the day value is 12 or lower allowing it to be easily interpreted as the month and vice versa. As a public service announcement, this comic states that there is in fact one international standard for writing numeric dates, set by the International Organization for Standardization in its ISO 8601 standard: YYYY-MM-DD.
The comic then proceeds to list several discouraged ways of writing out the date of the comic's publication, as they do not match the standard. It begins with several commonly used ones in countries around the world but then begins to list increasingly uncommon ways, ranging from strange (Roman numerals) to quirky (binary, Unix time) to essentially impossible (painting the numbers onto a black cat).
The title text provides a perfect example of the kind of ambiguity that can arise when non-standard formats are used. The ISO standard was in fact published on 1988-06-05 and amended on 2004-12-01. This is mentioned in the title text in MM/DD/YY format; however, there is no way to naturally figure this out, particularly with the second date.
With the year truncated to two digits and all three numbers at 12 or lower, the date referring to December 1, 2004 (the digits pairs 12, 01 and 04) has a number of misinterpretations. Usually 12th Jan '04 (if written as US-style but read as European, or vice-versa) but with ISO-influenced "YY MM DD" ordering as one side or other of the misunderstanding it can easily become the 12th day of April 2001, the 4th day of December 2001 and the 4th of January 2012. It takes two such communication errors to 'become' the 1st day of April 2012.
Date formats were again the subject in 1340: Unique Date and 2562: Formatting Meeting.
The other mentioned formats are:
- 02/27/2013
- MM/DD/YYYY, used mostly in the United States, Belize, and Micronesia.
- 02/27/13
- MM/DD/YY, same as above but with the year shortened to two digits.
- 27/02/2013
- DD/MM/YYYY, used variously in South America, Canada (officially uses ISO 8601), Australia, New Zealand, and much of Europe.
- 27/02/13
- DD/MM/YY, same as above but with the year shortened to two digits.
- 20130227
- YYYYMMDD, same as ISO 8601 without delimiting punctuation. Allowed by the standard. Technically not ambiguous but is hard to read as a date at first glance.
- 2013.02.27
- YYYY.MM.DD, used in Japan, South Korea, and Hungary. Same as ISO 8601 except with different punctuation.
- 27.02.13
- DD.MM.YY, used in Germany, Russia, and others.
- 27-02-13
- DD-MM-YY, used in Denmark, Netherlands, Indonesia, India, Bangladesh, and others.
- 27.2.13
- D.M.YY. It is common in several areas to abbreviate the month or day to a single digit and drop the leading zero when possible.
- 2013. II. 27.
- YYYY. MM. DD., with month as Roman numerals, used in Hungary. In this format, February and November are prone to be confused with each other: "II" vs. "11".
Similar formats with the opposite ordering (27. II. 2013) existed historically in various European countries like France, Germany, and Italy.
- 27⁄2-13
- D⁄M-YY, traditional format in Denmark, Norway, and Sweden
- 2013.158904109
- Year and decimal fraction of year. 0.158904109 is a decimal approximation of 58/365, with February 27 being the 58th day of the year. This format may be easier to read for computers/programs in some contexts, but is difficult for humans to interpret.
- MMXIII-II-XXVII
- The ISO 8601 standard but written in Roman numerals. Never used as a traditional standard anywhere as it is hard to read, parse, and interpret for no benefit.
- MMXIII LVII⁄CCCLXV
- Year followed by its partial fraction 57/365, all in Roman numerals. Equally useless as the above. As a note, apparently this 'standard' is different from the decimal fraction two rows above, as the decimal fraction notation uses the end of the day (first day of the year is 1/365 while the last is 365/365), while this uses the beginning (first day is 0/365 and last is 364/365).
- 1330300800
- UNIX Timestamp, a standard method of storing absolute time in many computer systems and defined as the number of seconds since 00:00:00 on 1970-01-01 (UTC). The Unix time listed here appears to mistakenly be for 2012-02-27, which is also mentioned by Randall in the original transcript. The Unix Timestamp for 2013-02-27 would be 1361923200.
- ((3+3)×(111+1)-1)×3/3-1/33
- A useless format where the numbers 2013, 2, and 27 written as needlessly long arithmetic expressions using just the digits 1 and 3. For additional confusion, the values are delimited by slashes, enabling confusion with the fraction bar. (If evaluated literally, the entire expression evaluates to 670.963, or 671 minus one twenty-seventh.)
- 2 272013
- A nearly impossible to read date "format" that can be considered a parody "compromise" between different formats: rather than argue about the order in which the year, month, and day should be, they are simply all written on top of each other. As a "bonus", there is also no arguing over which separator character to use.
- 10/11011/1101
- The US mm/dd/yy format in binary, corresponding to 2/27/13. Never used for obvious reasons.
- 02/27/20/13
- MM/DD/CC/YY, where CC stands for century. This format is never used. Note that while months and days count starting from 1, centuries and years in this format count from 0 for extra confusion. But the CC value is widely used on many operating systems to distinguish between the 20th and 21st century, represented by the values "19" and "20" because 1950 belongs to the 20th century.
2 3 1 4 0 1 2 3 7 5 67 8 - An obfuscated format where the small numbers indicate the positions where the respective large digits should be placed. In this reading, 0 is used at positions 2 and 5, 1 is used on position 3, etc. Coincidentally or not, positions 1 to 4 (the year) being all placed above their digits and 5 to 8 (month and day) below; the result being 20130227
- [A hissing black cat with "2-27-13" painted on it]
- In Western cultures, black cats and the number 13 are associated with bad luck. The cat might also just be angry that someone covered them in paint. Or maybe this is really the correct way.