“I find it troubling that an ISO committee is confusing terms taught in primary school science.”


Just to be clear, it isn’t the ISO committee that’s confusing these concepts – it’s ISO in general.  The committee draft has been reviewed by ISO editors (outside the committee) who have suggested that we change terminology (in the new material) to conform to existing ISO terminology, which uses “accuracy” rather than “precision”. For example, see the excerpt below from ISO 8601-2004  “Complete Representation” vs. “Representation with reduced accuracy”.   “Accuracy” here should instead be “precision”, but it has been “accuracy” since the first version of 8601 (many years ago) and nobody has noticed (or perhaps nobody cared enough, since the misuse of the terminology really has no effect on interoperability).  Our committee is not tasked with nor does it have the authority to fix this sort of thing, however, we are arguing that that does not mean we have to carry this mistake over to new material.


I just wanted to make it clear that the members of the current committee do understand the difference between these concepts.





_________________________________________________________________________________________ Complete representations

When the application identifies the need for a complete representation of a calendar date, it shall be one of

the numeric expressions as follows, where [YYYY] represents a calendar year, [MM] the ordinal number of a

calendar month within the calendar year, and [DD] the ordinal number of a calendar day within the calendar


Basic format: YYYYMMDD Example: 19850412

Extended format: YYYY-MM-DD Example: 1985-04-12 Representations with reduced accuracy

If in a given application it is sufficient to express a calendar date with less accuracy than a complete

representation as specified in, either two, four or six digits may be omitted, the omission starting from

the extreme right-hand side. The resulting representation will then indicate a month, a year or a century, as

set out below. When only [DD] is omitted, a separator shall be inserted between [YYYY] and [MM], but

separators shall not be used in the other representations with reduced accuracy.

a) A specific month

Basic format: YYYY-MM Example: 1985-04

Extended format: not applicable

b) A specific year

Basic format: YYYY Example: 1985

Extended format: not applicable

c) A specific century

Basic format: YY Example: 19

Extended format: not applicable