Go to Back Office / Rooms.
Click on the Room Type you want to edit. You will see "Edit Room Type".
Click on room rates
Click Add Special Rate. You can choose between 2 options:
Repeating date: if you want it to be repeated every year.
Specific date: if you want it to be applied only this time.
What if I have some dates that overlap?
If you have date period that over lap, the special rate ranked highest will be used. Drag and drop the rows using the arrow icons to place your special rate high on the top and set the priority of your special rates.