Sumproduct with Time Duration calculation

Originally Posted by Bob Phillips

Try this

=SUMPRODUCT(--(($C$2:$C$1000-$B$2:$B$1000)>=--"01:00:00"))

and there is no need to array-enter SUMPRODUCT

Thanks it works great.
My understanding was that you need array-enter with sumproduct, especially if you have multiple conditions.
Last what does the "--" after ">=" represent or mean?