I'm aiming to use RDF for weekly schedule description -- to
capture things like "7:00-9:00PM every Monday to Friday, and
4:00-10:00 every Saturday and Sunday" -- for originating new
data.

My understanding of how iCalendar represents repeated intervals
is embodied in the example below.  To capture the example
schedule above (7:00-9:00PM every Monday to Friday, and
4:00-10:00PM every Saturday and Sunday), I use something like
this:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:http://id.ninebynine.org/wip/2002/timetable
BEGIN:VEVENT
DTSTART:20021201T190000
DTEND:20021201T210000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:VEVENT
BEGIN:VEVENT
DTSTART:20021201T160000
DTEND:20021201T220000
RRULE:FREQ=WEEKLY;BYDAY=SA,SU
END:VEVENT
END:VCALENDAR