In addition to your basic rate for your product, you can also set a dependent period or seasonal rate.
1. Make a new price list (Tip sets the period in the name of the price list). Example : 2019-Shuttle-Summer-1-July-30-Sept.
Tip, You can easily copy price lists and eventual calculate with a surcharge or discount. See other article for the instructions.
2. Go to your product where you want to add 
3. Click on "Add rate for period". Choose the correct dates and corresponding price list. ( Tip, Good names of the previously made price lists are very useful here to make no mistakes ).
4. You can create rates for several periods, such as monthly rates, weekly rates, or a complete season.
5. How does it work? In principle, the basic rate is used when calculating the correct rate when making a reservation, but if there is also a period tariff entered, this will overrule the basic rate.
6. Note that the periods do not overlap.
the period rates.