Military Date-Time Group (DTG) Converter
Decode a military date-time group into UTC and local zone letters, check lists of DTGs and create the current DTG.
Runs in your browser. Your files never leave your device. See how to check
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How to do it
- 1Type or paste a DTG
Enter one DTG, or a list with one DTG per line.
- 2Choose the target zone letter
Pick the zone in which you want the same moment written.
- 3Read the result
See the UTC date and time, the source zone and the converted DTG.
- 4Fix invalid lines
A failed line names the rule it broke, such as a day that does not exist.
- 5Make the current DTG
Use the Make button to create the current time as a DTG in Zulu.
About this tool
Messages and orders in the military write time as a date-time group: two digits for the day, four for the time, a letter for the time zone, a three-letter month and the year, for example 211530ZOCT26. This tool decodes a DTG into a full UTC date and time, shows the zone letter with its offset, and converts it into the DTG in any other zone letter. Paste a whole list to check every line, copy the valid ones, or create the current DTG in UTC.
Who this is for Service members, cadets, emergency planners, radio operators and anyone who reads operational messages. It is also useful for writers and game designers who want realistic time stamps.
How a DTG is built DDHHMM is the day of the month, the hour in 24-hour time and the minute. The next letter is the time zone: Z is UTC (Zulu), A to I are one to nine hours ahead of UTC, K, L and M are ten, eleven and twelve hours ahead, and N to Y are one to twelve hours behind. The letter J is not used. The month is the first three letters in capitals and the year has two digits, with four digits sometimes used to avoid doubt.
What the tool checks It checks the pattern, that the zone letter exists, that the hour and minute are possible and that the day exists in that month, so 301200ZFEB26 is rejected. For a valid DTG it gives the UTC date and time in ISO form, the zone and its offset, the same instant written in the zone you choose and a UTC string.
Converting between zones Pick the target zone letter in the form. A DTG of 021200ROCT26 means noon on October 2 in zone R, which is five hours behind UTC, so it is 1700Z; written in zone A it would be 021800AOCT26.
Worked example 211530ZOCT26 is 15:30 UTC on October 21, 2026. In zone R (UTC−5) the same moment is 211030ROCT26, and in zone A (UTC+1) it is 211630AOCT26. The tool shows all three forms and checks the entire list at once.
Limits Zone letters are fixed hour offsets and do not follow daylight saving rules, so use the letter that matches the time in effect at the place. This is a converter, not an official standard document.
Worked example
The DTG 211530ZOCT26 decodes to 2026-10-21 15:30 UTC; in zone R it is 211030ROCT26 and in zone A it is 211630AOCT26.
Quick facts
- Category: UK & US
- Works in your browser, no sign-up, no upload.
- Your input stays on your device.
- Available in English.
- Content last reviewed:
- Official source: Allied communication publication conventions (DTG)
Frequently asked questions
What does the letter Z mean?
Z is Zulu time, which is UTC, the reference for all other zone letters.
Why is there no letter J?
J is used to mean the local time of the writer, so it is not a fixed zone and is skipped in the sequence.
Can I use a four-digit year?
Yes. Both 26 and 2026 are read as the year 2026.
What is checked?
The pattern, the zone letter, the hour and minute and that the day exists in the month.
Can I convert a list?
Yes. Paste one DTG per line, and download the table or copy the valid lines.
Does it handle daylight saving?
No. Zone letters are fixed offsets; choose the letter for the offset in force at the place and date.