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This article incorporates public domain material from "date-time group (DTG)". Federal Standard 1037C . General Services Administration. Archived from the original on 22 January 2022.
In communications messages, a date-time group (DTG) is a set of characters, usually in a prescribed format, used to express the year, the month, the day of the month, the hour of the day, the minute of the hour, and the time zone, if different from Coordinated Universal Time (UTC).[ citation needed ] The order in which these elements are presented may vary. The DTG is usually placed in the header of the message. One example is "21:49 Jun 22, 2025 (UTC)"; while another example is "21:49 22 Jun 2025".
The DTG may indicate either the date and time a message was dispatched by a transmitting station or the date and time it was handed into a transmission facility by a user or originator for dispatch.
The DTG may be used as a message identifier if it is unique for each message.
A form of DTG is used in the US military's Defense Message System (a form of Automated Message Handling System). In US military messages and communications (e.g., on maps showing troop movements) the format is DD HHMM (SS) Z MON YY. Although occasionally seen with spaces, it can also be written as a single string of characters. Three different formats can be found:
Z references the military identifier of time zone:
Example 1: 051100Z represents the 5th day of the current month 11:00 (UTC).
Example 2: 091630Tjul11 represents 9 July 2011 4:30 pm (MST).
Example 3: 22214909ZJun25 represents the current time of refresh: (Jun) 22 21:49:09, Jun 2025 (UTC).
This article incorporates public domain material from "date-time group (DTG)". Federal Standard 1037C . General Services Administration. Archived from the original on 22 January 2022.