Military time

In Canada and the United States, the term military time is a synonym for the 24-hour clock notation, which counts the hours of the day from 00 to 23. In these regions, the time of day is customarily given almost exclusively using the 12-hour clock notation, which counts the hours of the day as 12, 1, ..., 11 with suffixes 'a.m.' and 'p.m.' distinguishing the two diurnal repetitions of this sequence. The 24-hour clock is commonly known there only in a few specialist areas (military, aviation, navigation, meteorology, astronomy, computing, logistics, emergency services, hospitals), where the ambiguities of the 12-hour notation are deemed too inconvenient, cumbersome, or outright dangerous, with the military's use being historically the first and most famous example. The term "military time" has no particular meaning in most other regions of the world, where the 24-hour clock has long become a common element of every-day civilian life.

In the United States military, military time is similar to the 24-hour clock notation, with the exception that the colon is omitted and the time on the hours is often spoken as its decimal value. For instance, 6:00 a.m. would become 0600, and would be spoken as "zero six hundred" or "zero six zero zero". However none of these formatting or pronunciation details is in fact exclusively military, and all are common in the technical contexts in which the 24-hour clock is generally used in English-speaking countries.

For a more detailed discussion and practical examples, see the 24-hour clock article.

Differences between military and twenty-four hour time systems

• Written military time does not usually include a time separator (for example, "0340" is more common than the civilian "03:40").
• The first hour in military time is always "00"; civilian twenty-four hour systems may use "24" or "0".
• "Hours" is usually not appended in civilian use (15:00 may be pronounced "fifteen hundred hours", which is unusual in a non-military setting).
• Leading zeros are not pronounced in non-military usage (05:43 would be "five forty-three", as opposed to "oh five forty-three").
• Military timestamps on messages have the time zone where applicable appended; in a civilian setting, this would be redundant.

See also

• Comparison of the 12-hour and 24-hour clocks
• Date and time notation by country
• List of military time zones