Aer Lingus offers flexible flight date changes up to 2 hours before departure via “Manage My Booking” or +1 877‑310‑4366. Saver/Plus fares incur typical change fees (€40–USD 60 short-haul; €100–USD 150 long‑haul) plus fare difference. Advantage/Smart/Flex fares waive change fees—only fare difference applies. Travel must complete within 1 year https://americanairtravel.com/aer-lingus-flight-date-change-policy/