How To - Promotion - Flash deal
The main take away here is, you are creating a promo, that only appears for 36 hours on a scheduled date, to then book only allowed date range; room type etc.
e.g. not getting many reservations , so you boost a flash deal for the monthly rate plan for a certain room type.
and dont allow it to apply to premium days of the week i.e. Fridays , Saturdays.