[tei-council] <when>/@absolute and dateTime values

[Martin Holmes]

This bit of Chapter 8:

<http://www.tei-c.org/release/doc/tei-p5-doc/en/html/TS.html#TSSAPA>

contains this example:

<timeline unit="s" origin="#TS-P1">
  <when xml:id="TS-P1" absolute="12:20:01"/>
  <when xml:id="TS-P2" interval="4.5" since="#TS-P1"/>
  <when xml:id="TS-P6"/>
  <when xml:id="TS-P3" interval="1.5" since="#TS-P6"/>
</timeline>

with the following commentary:

"... TS-P1 is located absolutely, at 12:20:01:01 BST. TS-P2 is 4.5 
seconds later than TS-P2 (i.e. at 12:20:46)..."

I was first of all puzzled by the assertion that this is BST (British 
Summer Time). Nothing in the example suggests that there is any timezone 
offset from UTC, which I assumed was the default. Then I looked at the 
datatype for @absolute, which is data.temporal.w3c, about which we say 
in a note:

"If it is likely that the value used is to be compared with another, 
then a time zone indicator should always be included, and only the 
dateTime representation should be used."

<http://www.tei-c.org/release/doc/tei-p5-doc/en/html/ref-data.temporal.w3c.html>

So in this context, the xsd:dateTime representation should be used, and 
it should include a timezone. So I looked at the W3C spec:

<http://www.w3.org/TR/xmlschema-2/#dateTime>

which, as I read it, requires the presence of a date; whereas our 
example has only a time.

It seems to me, therefore, that this usage of @absolute is wrong on two 
counts: first, it should include a date, and second, it ought to have a 
timezone offset of 'Z', the canonical representation for an offset of 
zero, i.e. UTC. Further, I think the claim that this value is BST makes 
no sense (BST is UTC+1) given that the example has no timezone offset in it.

Am I missing anything here?

Cheers,
Martin