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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 standardizes all operations using Zulu time (UTC), which is based on the Prime Meridian, to eliminate confusion caused by local time zones and Daylight Saving Time.
Pilots use Zulu time for all flight planning and in-flight operations, converting to local time only upon landing by subtracting specific hours for each U.S. time zone, with an additional hour adjustment during Daylight Saving Time.
This global standardization ensures consistent timekeeping across the aviation community, regardless of whether specific locations observe Daylight Saving Time.

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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.