You are able to modify your flight before to departure with Aer Lingus's flight modification policy. In accordance with the terms and conditions, you will be responsible for the charge difference if you purchase an expensive ticket after selecting a less expensive flight. You can contact customer support by phone, on the Aer Lingus website, or by using the live chat feature to change your flight. When booking your tickets, make sure everything is correct because Aer Lingus may charge you more if you decide to change your schedule after 24 hours.
https://flightcancellationpoli....cy.com/aer-lingus-fl