Editing 24-hour clock (section)

=== Midnight 00:00 and 24:00 ===
{{redirect|23:59|the Christian metal album|Veni Domine#Discography|the film|23:59 (film)}}
In the 24-hour time notation, the day begins at midnight, 00:00 or 0:00, and the last minute of the day begins at 23:59. Where convenient, the notation 24:00 may also be used to refer to midnight at the end of a given date<ref>{{cite ISO standard |title=ISO 8601:2004 – Data elements and interchange formats – Information interchange – Representation of dates and times |csnumber=40874 |edition=3rd |at=Clause 4.2.3 "Midnight" |date=2004}}</ref>&nbsp;— that is, 24:00 of one day is the same time as 00:00 of the following day.

The notation 24:00 mainly serves to refer to the exact end of a day in a time interval. A typical usage is giving opening hours ending at midnight (e.g. "00:00–24:00", "07:00–24:00"). Similarly, some bus and train timetables show 00:00 as departure time and 24:00 as arrival time. Legal contracts often run from the start date at 00:00 until the end date at 24:00.

While the 24-hour notation unambiguously distinguishes between midnight at the start (00:00) and end (24:00) of any given date, there is no commonly accepted distinction among users of the 12-hour notation. [[Style guide]]s and military communication regulations in some English-speaking countries discourage the use of 24:00 even in the 24-hour notation, and recommend reporting times near midnight as 23:59 or 00:01 instead.<ref name=acp121>{{cite book |url=http://jcs.dtic.mil/j6/cceb/acps/acp121/ACP121I.pdf |title=Communication instructions – General |id=ACP 121(I) |page=3{{hyp}}6 |publisher=Combined Communications-Electronics Board |date=October 2010 |archive-url=https://web.archive.org/web/20110807210103/http://jcs.dtic.mil/j6/cceb/acps/acp121/ACP121I.pdf |archive-date=7 August 2011}}</ref> Sometimes the use of 00:00 is also avoided.<ref name=acp121 /> In variance with this, an older version of the correspondence manual for the [[United States Navy]] and [[United States Marine Corps]] specified 0001 to 2400.<ref>{{cite book |url=http://www.marforres.marines.mil/Portals/116/Docs/G-1/AAU/AAUDocuments/CORRESPONDENCE%20MANUAL.pdf |id=SECNAV M-5216.5 |title=Department of the Navy Correspondence Manual |date=March 2010 |publisher=[[United States Department of the Navy]] |at=Chapter 2, Section 5 Paragraph 15. Expressing Military Time}}</ref> The manual was updated in June 2015 to use 0000 to 2359.<ref>{{Cite book |url=https://www.marines.mil/Portals/59/Publications/SECNAV%20M%205216.5.pdf |id=SECNAV M-5216.5 |title=Department of the Navy Correspondence Manual |date=June 2015 |publisher=[[United States Department of the Navy]] |at=Chapter 2, Section 5 Paragraph 15. Expressing Military Time}}</ref>