WASHINGTON, July 18 (DC Times Online) — Daylight saving time is only a one-hour shift on the clock, but airlines say it can ripple through flight networks that cross time zones and borders.
Airlines for America, the U.S. trade group for major carriers, said in a July 14 update on airlines.org that changes to existing daylight saving time would have “considerable implications for aviation,” including passenger disruption, crew and aircraft positioning, and domestic and international connectivity. The group said airlines run “expansive interconnected domestic and global networks” that rely on “stability and predictability.”
What is the operational problem?
For airlines, time changes do not just affect departure boards. They can alter when crews are available, where aircraft end up after a flight, and whether connecting passengers make the next leg of a trip. A schedule that works in one time zone can stop working when another country changes clocks on a different date, or not at all.
That is why A4A said any change would need “an implementation timeline that reflects these global complications.”
Why do international routes matter?
A joint industry paper from Airlines for Europe, Airlines International Representation in Europe, the European Regions Airline Association and the International Air Transport Association made a similar argument. The paper said abolishing seasonal clock changes would have a significant impact on aviation and consumers in Europe and around the world, and it warned that any change should be synchronized across all EU member states to avoid chaos and missed flights.
The paper also said airlines would need at least 18 months’ notice to plan for a change. It said re-timing flights could require major rescheduling worldwide and could take years because airlines have to work around slot constraints, the takeoff and landing windows airports assign to carriers. As one example, the paper said the Europe-North America market includes more than 35,000 flights in July and August to and from congested EU airports.
Would the U.S. need Congress to act?
Under current federal law, daylight saving time is set nationwide, so a permanent change would go through Congress. That is one reason airline groups are treating the issue as a policy change with transportation consequences, not just a clock change.
The bottom line is simple: airlines can adjust to time changes, but they say the change has to be planned far in advance and coordinated across borders. In aviation, a one-hour shift can move crews, planes and passengers out of sync.