The surface accessibility of an airport is described by how easily potential passengers can reach it using their preferred mode of transport. Air travel often requires trips at irregular times, making it difficult to find available public transportation services and forcing the use of alternative modes such as ride-hailing or taxi services. Flight schedules are significantly impacted by time zones, aircraft bases, and crew hours, resulting in flights not corresponding with local bus or rail operating hours. This study focuses on Dublin Airport as a case study to explore how the availability of transportation options varies depending on the desired arrival time. The study utilises data such as flight schedules, public transport timetables, and spatial data to demonstrate how travel times to and from the airport vary greatly depending on the time of day. The findings highlight gaps in public transport and their impact on transportation choices. This paper presents a method that can be applied at an airport to analyse time-based accessibility using readily available data. The results aid airport operators in predicting passenger dwell times as they encourage a shift towards sustainable modes for access.