BEFORE you commence either CPL or IR skills course
Close - but not quite. If you have not completed the training for a night qualification before starting the CPL course (assuming you do this before the Instrument rating), then the standard 25 hour training course becomes a 30 hour course and must include the five hours of night training.
Haven't looked at the small print of the I/R to see what it says if you do the I/R first.