This depends on the fare class of your ticket. To make the change and check the cost, you can request it directly via the "My Booking" section or by email to [email protected].
Under the current ZEN policy, you can change your flight dates free of charge as long as the new flight dates stay within the same seasonality. If your new travel dates do change in season, we will calculate the difference for you. In all cases, please send your request to [email protected].