Resolution:
Description: CxxIcString holdPeriodAttr("NUM_DAYS");
              CxxIcInteger holdPeriodVal(
atoi(denyInfo.getHoldPeriod().data()) );
              icHoldTask.setAttribute(holdPeriodAttr, holdPeriodVal);
// This works!

              // Get calendar name from deny info table
              CxxIcString calendarNameAttr("CALENDAR_TYPE");
              CxxIcString
calendarNameVal(denyInfo.getCalendarName().data());
              cout << "CALENDAR_TYPE: " << calendarNameVal << endl;

    The cout looks like CALENDAR_TYPE: CALENDAR             which is
correct.

              status = icHoldTask.setAttribute(calendarNameAttr,
calendarNameVal);

              status.translate(511, statbuf);
              TraceLog(TRACE_INFORMATION, "icHoldTask.setAttribute: %s %s",
                   (const char*)icTaskName, statbuf);

The following is the output from the call to TraceLog.

10/22/99 13:39:33 : agent_OrderLetter - icHoldTask.setAttribute: Order
Letter RPC: Can't encode arguments

The setAttribute method will not set an icTask string attribute of 256 characters.
It is a limitation on IcString and affects any objects which have string attributes.

For certain databases such as Oracle the maximum string length was increased
to 2000 starting in TIBCO InConcert 6.0.