Q: Please clarify pattern constraint on date/time

The 17 December 1999 Draft of "XML Schema Part 1: Structures"
says:

> 2.5.2.4 pattern
> For subtypes of the date and time related types (timeInstant
> (§3.2.6), timeDuration (§3.2.7), recurringInstant (§3.2.8),
> date (§3.3.18) and time (§3.3.19)), pattern can be used to
> constrain the allowable values using IS0 8601 "pictures".

Which one of these does the spec mean to convey:
(1) the pattern must match a valid ISO8601 format, or
(2) the pattern can express new formats outside of those in
    ISO8601.

If either (1) or (2), the following patterns are OK:
  CCYY-MM-DD
  hh:mm:ss.sssZ
  YYMMDDThhmm

If (2), the following patterns are also OK:
  MM-DD-YY             (different order)
  CCYY/MM/DD           (different separator)
  CCYY-MM-DD hh:ss     (space rather than "T" separator)

Also, must the pattern be match exactly or only have an
equivalent value.  For example in ISO8601 some of the
separators are optional.  What if they are present in the
pattern and absent in the instance data?  What if the pattern
specifies "CCYYMM" and the instance data has all of that, but
also has more (such as "DD")?

Some examples in the spec would be very helpful.

Thanks, Randy

Received on Thursday, 6 January 2000 12:22:11 UTC