Why is UTC called Zulu time?

In the military time zone system, each UTC offset is assigned a letter of the alphabet. The letter Z designates UTC+0. Because the NATO phonetic alphabet renders Z as "Zulu," UTC+0 became known as Zulu time. The shorthand "Z" is commonly appended to timestamps in military, aviation, and maritime contexts.

What is the letter J (Juliet) in military time zones?

J (Juliet) is unique in the system: it does not correspond to a fixed UTC offset. Instead, it represents the observer’s local time, whatever that may be. This allows personnel to reference local time without specifying a particular offset.

Are military time zones still used today?

Yes. Military time zones are actively used in NATO operations, aviation (especially in flight plans and NOTAM notices), maritime navigation, and meteorological reports. Zulu time in particular is ubiquitous in aviation and is printed on every METAR weather report.

Military Time Zones and the NATO Phonetic System

June 25, 2026

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Why is UTC called Zulu time?: In the military time zone system, each UTC offset is assigned a letter of the alphabet. The letter Z designates UTC+0. Because the NATO phonetic alphabet renders Z as "Zulu," UTC+0 became known as Zulu time. The shorthand "Z" is commonly appended to timestamps in military, aviation, and maritime contexts.
What is the letter J (Juliet) in military time zones?: J (Juliet) is unique in the system: it does not correspond to a fixed UTC offset. Instead, it represents the observer’s local time, whatever that may be. This allows personnel to reference local time without specifying a particular offset.
Are military time zones still used today?: Yes. Military time zones are actively used in NATO operations, aviation (especially in flight plans and NOTAM notices), maritime navigation, and meteorological reports. Zulu time in particular is ubiquitous in aviation and is printed on every METAR weather report.