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What Impact Does Time Change Have on Aviation?

Here's how the aviation world navigates local time adjustments during daylight saving time.

Wednesday, March 15, 2023 at 11:07 AM ET

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Edited By: tccjeremy

The aviation world uses Zulu time, which is derived from the Prime Meridian running through Greenwich, England. [Credit: Shutterstock]

Key Takeaways:

Aviation universally uses "Zulu time" (also known as Coordinated Universal Time or UTC), which is derived from the Prime Meridian, to avoid complications from local time zones and Daylight Saving Time.
Pilots operate on Zulu time throughout their flights and only convert to local time after landing, simplifying global flight operations.
While Zulu time negates in-flight adjustments for Daylight Saving Time, pilots factor in an additional hour when converting Zulu time to local time during DST periods.

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Question: My workplace is struggling with the switch to daylight saving time and I’m wondering, what impact does losing an hour in the spring and gaining an hour in the fall have on aviation? I heard there are some states in the U.S. that don’t observe daylight saving time—doesn’t that mess things up for air travel?

Answer: The aviation world uses Zulu time, which is derived from the Prime Meridian running through Greenwich, England. Instead of having to convert to local time or local time adjusted for daylight saving time, pilots use Zulu time—adjusting to local time after they land.

Meridians are imaginary lines that run north and south, or longitudinally, stretching from the North to South poles. The Prime Meridian is the zero line, from which measurements are made in degrees east (E) and west (W) to 180 degrees. This is where time zones begin.

Meg Godlewski has been an aviation journalist for more than 24 years and a CFI for more than 20 years. If she is not flying or teaching aviation, she is writing about it. Meg is a founding member of the Pilot Proficiency Center at EAA AirVenture and excels at the application of simulation technology to flatten the learning curve. Follow Meg on Twitter @2Lewski.