Basics · 24-hour clock

Military time & the 24-hour clock in Eastern Time

Military time counts from 0000 to 2359: add 12 to any PM hour, so 2:00 PM ET is 1400. Eastern Time is zone Romeo (R, UTC−5) in winter and Quebec (Q, UTC−4) in summer, so 1400R equals 1900Z.

Eastern Time now
----R
Zulu (UTC) now
----Z
ET zone letters
R in EST · Q in EDT
ET to Zulu
+5 h (EST) · +4 h (EDT)

How do you read and say military time?

The 24-hour clock writes every time as four digits with no colon and no AM or PM. The first two digits count hours since midnight, the last two are minutes. Leading zeros are spoken as "zero", and whole hours as "hundred", never "thousand". Many Americans add "hours".

  • 0000: "zero hundred", midnight at the start of the day
  • 0630: "zero six thirty"
  • 1000: "ten hundred"
  • 1300: "thirteen hundred" or "thirteen hundred hours"
  • 1545: "fifteen forty-five"
  • 2359: "twenty-three fifty-nine", the last minute of the day

On the radio, digits are often read one by one ("zero five four three").

Is midnight 0000 or 2400?

Both name the same instant: 0000 starts a day, 2400 ends it. A shift ending at 2400 on November 7 ends at 0000 on November 8. Because that invites date errors, the US Navy and Marine Corps correspondence manual has used the range 0000–2359 since 2015, and many schedules write 2359 instead of 2400. The Navy adopted the 24-hour clock in 1920; the Army made it official on July 1, 1942.

Ruler comparing Eastern Standard Time on the 24-hour clock with Zulu time: 0000 EST is 0500Z, and 1900 EST is 0000Z on the next UTC day ESTZulu AMPM next UTC day 000003000600090012001500180021002400 0500Z0800Z1100Z1400Z1700Z2000Z2300Z0200Z0500Z 1900R = 0000Z
During EST, Zulu runs 5 hours ahead; in EDT the gap is 4 hours.

How do you convert 12-hour time to military time?

  1. 12:00–12:59 AM: write 00 for the hour. 12:30 AM is 0030.
  2. 1:00–11:59 AM: keep the hour and pad it to two digits. 7:05 AM is 0705.
  3. 12:00–12:59 PM: keep 12. 12:45 PM is 1245.
  4. 1:00–11:59 PM: add 12 to the hour. 6:20 PM is 1820.

To go back, subtract 12 from any hour of 13 or more and add PM; 00 becomes 12 AM. To reach Zulu, add 5 hours while Eastern Time is on EST and 4 while it is on EDT, and move to the next date if the result passes 2400. The reasoning behind those two numbers is on our Eastern Time UTC offset page, and EST to UTC covers the conversion in detail.

Eastern Time to military time and Zulu: hour-by-hour table

Every hour of an ordinary day in Eastern Time. "Next day" means the UTC date is one day later.
12-hour (ET)24-hour (ET)Zulu during EST (R)Zulu during EDT (Q)
12:00 AM00000500Z0400Z
1:00 AM01000600Z0500Z
2:00 AM02000700Z0600Z
3:00 AM03000800Z0700Z
4:00 AM04000900Z0800Z
5:00 AM05001000Z0900Z
6:00 AM06001100Z1000Z
7:00 AM07001200Z1100Z
8:00 AM08001300Z1200Z
9:00 AM09001400Z1300Z
10:00 AM10001500Z1400Z
11:00 AM11001600Z1500Z
12:00 PM12001700Z1600Z
1:00 PM13001800Z1700Z
2:00 PM14001900Z1800Z
3:00 PM15002000Z1900Z
4:00 PM16002100Z2000Z
5:00 PM17002200Z2100Z
6:00 PM18002300Z2200Z
7:00 PM19000000Z (next day)2300Z
8:00 PM20000100Z (next day)0000Z (next day)
9:00 PM21000200Z (next day)0100Z (next day)
10:00 PM22000300Z (next day)0200Z (next day)
11:00 PM23000400Z (next day)0300Z (next day)

On the spring-forward night (March 14, 2027) the 0200 hour does not exist in Eastern Time; on the fall-back night (November 7, 2027) the 0100 hour happens twice.

What are the military time zone letters for Eastern Time?

NATO and US forces label each whole-hour offset with a letter, read in the phonetic alphabet; the system is published by the Combined Communications-Electronics Board in ACP 121. The letters belong to offsets, not to named zones, so Eastern Time changes letter twice a year: R from November to March and Q from March to November.

The letter is what keeps the repeated hour apart. On November 7, 2027, 1:30 AM happens twice: first as 0130Q (0530Z), then, after clocks fall back, as 0130R (0630Z). Civilian labels such as EST and EDT are compared on our time zone abbreviations page.

Military zone letters around Eastern Time
LetterNameOffsetMatches
ZZuluUTC±0UTC itself
QQuebecUTC−4EDT (also AST)
RRomeoUTC−5EST (also CDT)
SSierraUTC−6CST (also MDT)
JJuliettlocalthe observer's local time

How do you write a date-time group (DTG)?

Military messages stamp time as a date-time group: two-digit day, four-digit time, zone letter, three-letter month and two-digit year, in the pattern DDHHMMZ MON YY. 2:00 PM EST on Saturday, November 7, 2026 is written:

071400R NOV 26

The same instant in UTC, the form normally used in formal message traffic, is 071900Z NOV 26. Software often runs the parts together (071900ZNOV26), and planners drop month and year when context makes them obvious (071900Z). Right now the DTG is loading…, which is loading….

Why do aviation and the military use Zulu time?

A flight from Boston to Chicago crosses a zone line, and a deployment can cross a dozen. One clock for everyone removes three sources of error: no conversion between zones, no daylight saving change (UTC never springs forward) and no AM/PM confusion. International aviation rules set by ICAO therefore require UTC on the 24-hour clock, so flight plans, NOTAMs and weather reports carry stamps such as 071953Z. A pilot based in the Eastern zone adds 5 hours in winter and 4 in summer, which is why the offset matters more than the local name. For terms such as UTC, GMT and ISO 8601, see the time zone glossary; for today's local time, the live Eastern Time clock; and for the winter–summer switch itself, EST vs EDT.

Convert an Eastern time to Zulu

Enter a time in ET; the result shows the UTC equivalent in 12-hour form. Read it as Zulu with the rules above, or open the full time zone converter.

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Frequently asked questions

Is military time the same as the 24-hour clock?

Mostly. Much of the world uses the 24-hour clock every day, written with a colon (14:00). "Military time" is the common US name for it, plus military habits: no colon, hours spoken as "hundred", and a zone letter.

Does military time change with daylight saving time?

The local reading does not: 1400 on a summer afternoon is still 2:00 PM on the wall clock. What changes is the zone letter and the Zulu equivalent: 1400Q is 1800Z, while 1400R is 1900Z. Zulu itself never changes.

How do you write seconds in military time?

Add two more digits: 143005 is 2:30:05 PM. In ISO 8601 the same time is 14:30:05, and a full Eastern timestamp looks like 2026-11-07T14:30:05-05:00.

Which letters do Central and Pacific Time use?

Central Time is S (Sierra, UTC−6) in standard time and R (Romeo, UTC−5) in daylight time. Pacific Time is U (Uniform, UTC−8) for PST and T (Tango, UTC−7) for PDT.

Explore

EST vs EDT

Why the zone letter flips between R and Q each year.

UTC offset

UTC−5 and UTC−4 explained, with notation tips.

EST to UTC

Hour-by-hour Eastern to UTC conversion for both seasons.

Glossary

Short definitions of 30+ time zone terms.

Converter

Convert ET to any major zone, DST-aware.