For example if you want to insert a discount for reservations taking the entire August month you can insert a cost with negative value (also as percentage) and associate it, when possible, to desired rates applying it only to reservations of 30 or more days. After you set only the August month in the permitted periods of the cost. You can even give the discount only to the first reservations setting a limit for the number of contemporaneous costs.
Discounts can be offered also to last minute or early reservations, thanks to the extra costs ability to be associated depending on the number of days left to the beginning of the reservation when it is inserted. Finally dicounts for groups can also be added, taking advantage of the possibility to associate a cost depending on the number of reservations being inserted contemporaneously.