SMIL 2.0 - Duration of Last Call Period?

I was wondering if anyone knows the intended duration of the last call period 
for the 1st March 2001 WD of SMIL 2.0. I was unable to locate a statement as 
to the duration of the last call period in the part of the WD where I would 
typically expect to find it.

I also noticed that mention is made of the XHTML + SMIL profile. Does 
progress of SMIL 2.0 to CR, depend on further progress on XHTML+SMIL?

Andrew Watt