return null;
}
CalendarValue in = (CalendarValue)av1.getPrimitiveValue();
int nargs = argument.length;
SecondsDurationValue tz = null;
if (nargs==1) {
// use the implicit timezone
tz = (SecondsDurationValue)new DateTimeValue(c).getComponent(Component.TIMEZONE);
return in.setTimezone(tz);
} else {