Timing - Historical References

Following are some useful references from member-tt archives (member only
access).

The first [1] shows an early model for time containers rooted at the tt
element. The second [2] shows why (and where) we began pushing this down to
body.

[1] https://lists.w3.org/Archives/Member/member-tt/2005Jan/0065.html
[2] https://lists.w3.org/Archives/Member/member-tt/2005Oct/0011.html

In both contexts, the phrase "external time interval" is what we now call
"root temporal interval", and which was intended to refer to an interval of
time established by the external processing context, and not intrinsically
tied to the document. But see also Dave Singer's comment on [2] at [3],
where he implies two different possible notions of this interval:

   - as determined by the "outside" (external processing context)
   - as determined by the "inside" (the document itself)

[3] https://lists.w3.org/Archives/Member/member-tt/2005Oct/0014.html