I would surely never water my Orchids according to a tight schedule like that, made up by someone who has probably no idea of how sunny/bright, well ventilated or not, what temperature etc etc, what your growing conditions are.
I would check the medium, if it is approaching dryness I would water the Orchid thoroughly, let it drip off and put it back into its spot. Whatever the day of the week! If you water your Brassia as suggested by the vendor, you might look at accordion pleats on your plant in no time flat.
