In Booking manager system you can setup a discount for charter in a specific period to be calculated automatically which is the best way to setup special offers for a particular period.
The Discount manager can be found in Setup (1.) > Discount types (2.).
Press New (1.) to open a new discount and give the Discount name (2.) and press Apply (3.).
Now the discount has appeared in the list on the left so you click on it (1.). Next set the Trigger type to Service period (2.). Next set the Start date (3.) and End date (4.) of the charter then set the Default value of the discount (5.) and press Apply (6.).
Additional thing which makes this trigger type very useful for special offers is that the order period can also be limited for such a discount.
You can set the Order period to be Valid from (1.) and Valid untill (2.) and press Apply (3.)
This example gives the discount that is valid for sailing in August that can only be booked in July.
Additional flexibility to creating such a discount is given with two features that can be found in Advanced section (1.)
Here if you place a check on Exclude other discounts (2.) and remove the check from Affected by maximum (3.) and press Apply (4.) you will get a discount that will not apply other discounts and can ignore the maximum discount set in Reservation settings (if required) that will be applied only in the timeframe set for the Service and Order period.
Now this name of the option can be translated by pressing the flag. After you pressed the flag button a list of flags repesenting their respective languages will appear. The list consists of 18 languages. The red ones are not translated.
For more details please refer to Translating the Options and Discounts