Zulu time converter.

How to convert a time to Zulu

Zulu time is UTC. To get there from a local time, find the zone's offset from UTC and subtract it: Zulu = local time - offset. Eastern Standard Time is UTC-5, so 09:00 EST is 09:00 - (-5) = 14:00 Zulu. Eastern Daylight Time is UTC-4, so 09:00 EDT is 13:00 Zulu. West of the prime meridian you add hours, east of it you subtract them. Military time is then written without a colon, so 14:00 Zulu is 1400Z, said "fourteen hundred Zulu".

Worked example (hypothetical)

A 22:30 call on 14 March in zone U (UTC-8, Pacific Standard Time) is 22:30 + 8 hours = 30:30, which is 06:30 on 15 March Zulu. The date moves a day forward, so the Zulu form is 0630Z on the 15th. Going the other way, 0200Z read in zone A (UTC+1) is 03:00, and read in zone S (UTC-6) it is 20:00 the day before. The tool does that date arithmetic for you and lists the same moment in all 25 lettered zones.

Zulu, UTC and GMT

For everyday conversions Zulu, UTC and "GMT" give the same clock reading. They are not the same thing as London's civil time: the United Kingdom is on UTC+0 in winter and UTC+1 in summer, so London matches Zulu only for part of the year. Zulu never changes with daylight saving time. That is why it is used to line up people in many zones: the number does not depend on who is reading it.

Daylight saving and fixed letters

When you choose "My browser time zone" the tool asks your browser for the exact offset on the date you entered, including daylight saving time. A lettered zone is a fixed offset, so choosing Romeo means exactly UTC-5 even in July. If a time was written in a summer civil zone, pick that zone's current letter (Quebec for New York in July) or use the browser option. A local time that does not exist (the spring clock jump) is read with the offset before the change; an ambiguous one (the autumn repeat) uses the first of the two.

Common mistakes

Using Romeo for "Eastern" all year, forgetting that the date can roll over, reading J as a real zone (J means the writer's local time, so it cannot be converted), and treating the half-hour zones as if a letter existed: India (UTC+5:30) has no letter. Email headers that show a letter instead of +0000 are covered on the military time zone letters page.

Who this is for

People who meet Zulu times in aviation, shipping, emergency management, amateur radio, cadet programs, gaming communities and fiction, and anyone who needs to read a "1400Z" in a briefing or log.

What this does not cover

It converts clock times only. It does not give sunrise, a time source or an official time signal, and it is not a timekeeping authority. For named places and meeting planning use the meeting planner; for epoch values use the Unix timestamp converter; to write the result as a date-time group use the DTG formatter.

FAQ

What is Zulu time?

Zulu time is the military name for Coordinated Universal Time (UTC), the zone with the letter Z and a UTC offset of zero. Times are written in 24-hour form, such as 1400Z.

How do I convert EST to Zulu?

Add 5 hours: Eastern Standard Time is UTC-5, so 09:00 EST is 14:00 Zulu. During daylight time (EDT, UTC-4) add 4 hours.

How do I convert Zulu to local time?

Subtract the zone's west offset or add its east offset. 1400Z is 09:00 in zone R (UTC-5) and 15:00 in zone A (UTC+1). Enter the time as Zulu in this tool to see every zone at once.

Is Zulu time the same as GMT?

For the clock reading, yes. But London is on GMT only in winter; in summer it is on UTC+1. Zulu does not change with the seasons.

Does Zulu time change with daylight saving time?

No. Zulu is UTC and has no daylight saving time. The local zones that observe it change their offset instead.

How do you say 1430Z?

It is read "fourteen thirty Zulu". The first two digits are hours on a 24-hour clock and the last two are minutes.

What does J mean when converting to Zulu?

J means the local time of whoever wrote the time. It has no UTC offset, so it cannot be converted without knowing the writer's location.

Is my time sent anywhere?

No. The conversion runs entirely in your browser and nothing you enter is stored.

Sources (each opened 2026-10-20): Wikipedia, List of military time zones (cites ACP 121(I), CCEB, October 2010); Wikipedia, Date-time group (cites MIL-STD-2500A and Federal Standard 1037C). Offsets for IANA-named zones come from your browser's own time zone database (Intl API), not from these pages.