Short answer: Zulu time is Coordinated Universal Time (UTC), the single time standard used in aviation worldwide. Weather reports, forecasts, NOTAMs and flight plans all use it so there’s no confusion across time zones. To convert, add or subtract your time zone’s offset, which changes by one hour when daylight saving time begins or ends.
U.S. Time Zone Offsets
| Zone | Standard time | Daylight time |
|---|---|---|
| Eastern | UTC −5 | UTC −4 |
| Central | UTC −6 | UTC −5 |
| Mountain | UTC −7 | UTC −6 |
| Pacific | UTC −8 | UTC −7 |
| Alaska | UTC −9 | UTC −8 |
| Hawaii | UTC −10 | No DST |
Arizona (except the Navajo Nation) stays on Mountain Standard Time year-round.
Worked Example
A TAF valid from 1800Z, read in Seattle during daylight saving time (UTC −7): 1800 − 7 = 1100 local. In winter (UTC −8), the same 1800Z is 1000 local. Watch for date changes. 0300Z on the 15th is the evening of the 14th in the U.S.
Tips
- Set a second clock on your phone or panel to UTC.
- Always check whether daylight saving time is in effect.
- When in doubt, ask Flight Service or check your EFB, which can display both.
The Bottom Line
Aviation runs on one clock. Learn your local offset for both standard and daylight time, watch for date changes, and you’ll read every report correctly.
Frequently Asked Questions
Why is it called Zulu?
“Z” is the military time zone letter for UTC, and “Zulu” is its phonetic name.
Is Zulu the same as GMT?
For practical purposes in aviation, yes.
What’s the Pacific offset in summer?
UTC −7.
Sources: FAA — Aeronautical Information Manual; FAA — Pilot’s Handbook of Aeronautical Knowledge
