Time Zones
Zulu Time Explained: UTC, Military Time Zone Letters and Conversions
Zulu time is Coordinated Universal Time (UTC). What the Z means, all 25 military time zone letters, U.S. zone letters for standard and daylight time, and how to convert local time to Zulu.
By Free Military Time Calculator Team ·
Zulu time is Coordinated Universal Time (UTC), the time at the Prime Meridian with a zero offset, written with a Z after the time: 1430Z means 1430 UTC. The military, aviation, shipping and weather services use Zulu so every station shares one clock.
Why It Is Called Zulu
Military time zones are named with letters. The zero-offset zone has the letter Z, and Z is “Zulu” in the NATO phonetic alphabet. Greenwich Mean Time (GMT) shows the same clock time as UTC.
The 25 Military Time Zone Letters
The letters run east and west from Zulu:
- A (Alpha) to M (Mike): UTC+1 to UTC+12, east of Greenwich. J is skipped.
- N (November) to Y (Yankee): UTC−1 to UTC−12, west of Greenwich.
- Z (Zulu): UTC±0.
- J (Juliet): local time wherever the writer is, with no fixed offset.
A time with a letter names its zone: 0600R is 6:00 AM in the Romeo zone (UTC−5).
U.S. Time Zones in Zulu
| Zone | Standard time | Daylight time |
|---|---|---|
| Eastern | R (Romeo), UTC−5 | Q (Quebec), UTC−4 |
| Central | S (Sierra), UTC−6 | R (Romeo), UTC−5 |
| Mountain | T (Tango), UTC−7 | S (Sierra), UTC−6 |
| Pacific | U (Uniform), UTC−8 | T (Tango), UTC−7 |
| Alaska | V (Victor), UTC−9 | U (Uniform), UTC−8 |
| Hawaii | W (Whiskey), UTC−10 | No daylight saving |
How to Convert Local Time to Zulu
To convert local time to Zulu, subtract the zone’s UTC offset. Western zones have negative offsets, so subtracting adds hours.
- 1400 Eastern Standard Time (UTC−5): 1400 + 5 = 1900Z.
- 1400 Eastern Daylight Time (UTC−4): 1400 + 4 = 1800Z.
- 2100 Pacific Standard Time (UTC−8): 2100 + 8 = 2900 → 2900 − 2400 = 0500Z the next day.
How to Convert Zulu to Local Time
Add the zone’s offset: 1900Z in Central Standard Time (UTC−6) is 1900 − 6 = 1300 CST. Subtract 24 or add 24 and change the date, if the result goes past midnight.
Daylight Saving Time and Zulu
Zulu never changes for daylight saving time; local zones do. U.S. daylight saving time runs from the second Sunday in March to the first Sunday in November, so Eastern time is 5 hours behind Zulu in winter and 4 hours behind in summer.
Where You See Zulu Time
- Aviation: flight plans, weather reports and air traffic use UTC.
- Military messages: date-time groups such as 091530Z NOV 26.
- Shipping and radio: logs use UTC so every station agrees.
- Computing: servers often store timestamps in UTC.
Convert any time with the military time zone converter or see Zulu live on the current military time page.