a remark for subscribers from the U.S.:
The actual only real exclusion are a few English-speaking region, in which nevertheless notations with time between 1 and 12 and improvements like “a.m.” and “p.m.” have been in wider incorporate. The common 24h international common notation try popular now even in England (e.g. at flight terminals, movies, bus/train timetables, etc.). Other dialects do not have even abbreviations like “a.m.” and “p.m.” plus the 12h notation is obviously rarely utilized on Continental European countries to create or display a period of time. In the U.S., the armed forces and desktop code writers have used the 24h notation for quite some time.
The existing English 12h notation has many negatives like:
- It really is more than the conventional 24h notation.
- It will require significantly longer for individuals examine two times in 12h notation.
- It isn’t obvious, exactly how 00:00, 12:00 and 24:00 become symbolized. Even encyclopedias and magnificence manuals have contradicting information and a standard fast solution is apparently to avoid “12:00 a.m./p.m.” entirely and compose “noon”, “midnight”, or “12:01 a.m./p.m.” instead, although the phrase “midnight” however doesn’t separate between 00:00 and 24:00 (midnight in the beginning or conclusion of a given day).
- It generates anyone typically believe the very next day starts within overflow from “12:59 a.m.” to “1:00 a.m.”, and that’s a common difficulty just when individuals try to training the timer of VCRs after midnight.
- It’s not conveniently similar with a sequence review procedure.
- It isn’t immediately obvious for oblivious, if the time passed between “12:00 a.m./p.m.” and “1:00 a.m./p.m.” initiate at 00:00 or at 12:00, i.e. the English 12h notation is more hard to realize.
Please consider the 12h time to end up being a relic from dark many years whenever Roman numerals were used, the number zero hadn’t however come to exist and analogue clocks comprise the only recognized as a type of showing a period. Be sure to stay away from it today, particularly in technical software! Even in the U.S. 
, the commonly trustworthy Chicago guide of Style now advises using the intercontinental common time notation in publications.
a comment for subscribers from German-speaking nations:
The German criterion DIN 5008, which specifies typographical policies for German messages created on typewriters, had been upgraded in 1996-05. The old German numeric big date notations DD.MM.YYYY and DD.MM.YY have-been changed by ISO time notations YYYY-MM-DD and YY-MM-DD. In the same way, the outdated German energy notations hh.mm and hh.mm.ss happen replaced by the ISO notations hh:mm and hh:mm:ss. Those latest notations have become additionally discussed during the current version with the Duden . The German alphanumeric date notation has been like “3. August 1994” or “3. Aug. 1994”. The related Austrian requirement has used the ISO 8601 date and time notations prior to.
ISO 8601 happens to be used as European traditional EN 28601 and it is for that reason now a valid criterion in every EU region and all sorts of conflicting nationwide specifications happen changed correctly.
Times zone
Without having any additional additions, a romantic date and times as composed over is actually believed to stay in some regional opportunity region. In order to show that a time is determined in worldwide Time (UTC), possible append a capital letter Z to an occasion like in
23:59:59Z or 2359Z
Mention: The Z signifies the “zero meridian”, which undergoes Greenwich in London, and it’s also additionally popular in radio communication in which truly obvious “Zulu” (the term for Z inside worldwide broadcast alphabet). Worldwide Time (sometimes also called “Zulu Time”) had been also known as Greenwich mean-time (GMT) before 1972, but this name should not any longer be utilized. Ever since the introduction of a global atomic times size, just about all present municipal opportunity areas are now actually regarding UTC, which is slightly distinctive from the existing and from now on abandoned GMT.]