Military Timezone Codes — Alpha to Zulu
Reference guide for the 25 military timezone codes from Alpha (UTC+1) to Zulu (UTC+0). Used in military, aviation, and nautical communications.
Concepts
Detailed Explanation
Military Timezone Codes (NATO Phonetic Timezone System)
Military time zones are a set of 25 single-letter designations (A-Z, excluding J) used by the military, aviation, and maritime industries to unambiguously specify timezone offsets.
The Complete List
| Letter | Name | UTC Offset |
|---|---|---|
| A | Alpha | UTC+01:00 |
| B | Bravo | UTC+02:00 |
| C | Charlie | UTC+03:00 |
| D | Delta | UTC+04:00 |
| E | Echo | UTC+05:00 |
| F | Foxtrot | UTC+06:00 |
| G | Golf | UTC+07:00 |
| H | Hotel | UTC+08:00 |
| I | India | UTC+09:00 |
| K | Kilo | UTC+10:00 |
| L | Lima | UTC+11:00 |
| M | Mike | UTC+12:00 |
| N | November | UTC-01:00 |
| O | Oscar | UTC-02:00 |
| P | Papa | UTC-03:00 |
| Q | Quebec | UTC-04:00 |
| R | Romeo | UTC-05:00 |
| S | Sierra | UTC-06:00 |
| T | Tango | UTC-07:00 |
| U | Uniform | UTC-08:00 |
| V | Victor | UTC-09:00 |
| W | Whiskey | UTC-10:00 |
| X | X-ray | UTC-11:00 |
| Y | Yankee | UTC-12:00 |
| Z | Zulu | UTC+00:00 |
Why "J" Is Skipped
The letter J (Juliet) is intentionally omitted. In military usage, J refers to the local time of the observer, which varies by location. This avoids confusion when the observer's exact timezone is unknown.
Zulu Time
Z (Zulu) is the most commonly encountered military timezone code. It represents UTC+00:00 and is the origin of the "Z" suffix in ISO 8601 timestamps:
2024-03-15T14:30:00Z ← The "Z" means Zulu time (UTC)
Usage in Aviation
Aviation uses Zulu time universally for flight plans, NOTAMs (Notices to Air Missions), METARs (weather reports), and ATC communications:
METAR KJFK 151430Z 27010KT 10SM FEW250 18/06 A3012
↑ 14:30 Zulu (UTC)
Pattern: East Is Positive, West Is Negative
Letters A through M (positive offsets) move eastward from Greenwich. Letters N through Y (negative offsets) move westward. This forms a logical geographic progression around the globe.
Use Case
Military timezone codes appear in aviation METARs and TAFs, military communication timestamps, nautical ship logs, NATO operational messages, and some legacy systems. Developers building aviation software, military logistics platforms, or systems that parse METAR weather data need to convert these single-letter codes to UTC offsets.