In Booking manager system you can setup a discount for 2-week charter to be calculated automatically.
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 duration (2.). Next set the Duration of the charter (3.) from 14 to 20 days, set the Order period (4.) in which the discount will be offered (if it applies), then set the Value of the discount (5.) and press Apply (6.) again.
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