[DFDL-WG] More Date/Time/DateTime Clarifications

[Steve Lawrence]

We need a couple more clarifications on implementing date/time/dateTime 
in Daffodil.

1) What is the expected infoset output? The spec seems to be silent on 
this issue. Based on some tests we received from IBM, it looks like this 
makes sense:

xs:date     = uuuu-MM-ddxxx
xs:time     = HH:mm:ss.SSSSSSxxx
xs:dateTime = uuuu-MM-dd'T'HH:mm:ss.SSSSSSxxx

Points of interest:
- uuuu instead of yyyy. The u allows for negative years, which is needed 
to represent BC dates
- There are 6 significant figures for fractional seconds
- Timezone is represented as xxx, since UTC is represented as +00:00 
instead of 'Z' in the IBM tests we have

Does this seem correct?


2) We would like some confirmation on the patterns for 
calendarPatternKind="implicit"?

The current spec has:

xs:date     = yyyy-MM-dd
xs:time     = HH:mm:ssZZZ
xs:dateTime = yyyy-MM-dd'T'HH:mm:ss

The IBM tests we have match these patterns except for the timezone 
pattern for xs:time. The ZZZ pattern matches -0800, however, the IBM 
test we have parse -08:00. This could be represented with a few 
different patterns (e.g. ZZZZZ, XXX, xxx, xxxxx). We're unsure if the 
IBM tests are incorrect of if the spec needs to be updated.

It also seems odd to me that the xs:time pattern has a timezone whereas 
dateTime does not. I'm not arguing it's wrong, just that it's not 
intuitive to me.


Note that we don't have IBM's tool set up yet, so we can't verify if the 
tests we have actually represent IBM behavior.

Thanks,
- Steve