Yes, you can set special high season or low season prices for certain dates for your Property. This can be done in My Property section of your Personal Account before publishing your Listing. In the lower part of the screen you will find a Change Parameters button. Click on it and you will be able to set parameters of your Listing.
When you start setting your Listing parameters at step 1 you will be asked to set a base price, which will be applied to all the nights at the Property offered by you. At step 3 you will be able to set season prices for certain dates or periods that you offer. Any discounts that you set for your Listing will apply equally to base price and all season prices.