Editing Time zone (section)

== Notation ==

=== ISO 8601 ===
{{Main|ISO 8601}}

ISO 8601 is a standard established by the [[International Organization for Standardization]] defining methods of representing dates and times in textual form, including specifications for representing time zones.

If a time is in [[Coordinated Universal Time]] (UTC), a "Z" is added directly after the time without a separating space. "Z" is the zone designator for the zero UTC offset. "09:30&nbsp;UTC" is therefore represented as "09:30Z" or "0930Z". Likewise, "14:45:15&nbsp;UTC" is written as "14:45:15Z" or "144515Z".<ref name="ZuluTime">{{Cite web|url=https://www.timeanddate.com/time/zones/z|title=Z – Zulu Time Zone (Time Zone Abbreviation)|website=TimeAndDate.com|language=en|access-date=August 22, 2018|archive-date=August 22, 2018|archive-url=https://web.archive.org/web/20180822145905/https://www.timeanddate.com/time/zones/z|url-status=live}}</ref> UTC time is also known as "Zulu" time, since "Zulu" is a [[ICAO spelling alphabet|phonetic alphabet]] code word for the letter "Z".<ref name="ZuluTime"/>

[[UTC offset|Offsets from UTC]] are written in the format ±hh:mm, ±hhmm, or ±hh (either hours ahead or behind UTC). For example, if the time being described is one hour ahead of UTC (such as the time in [[Germany]] during the winter), the zone designator would be "[[UTC+01:00|+01:00]]", "+0100", or simply "+01". This numeric representation of time zones is appended to local times in the same way that alphabetic time zone abbreviations (or "Z", as above) are appended. The offset from UTC changes with [[daylight saving time]], e.g. a time offset in [[Chicago]], which is in the [[Central Time Zone (North America)|North American Central Time Zone]], is "[[UTC−06:00|−06:00]]" for the winter (Central Standard Time) and "[[UTC−05:00|−05:00]]" for the summer (Central Daylight Time).<ref>{{Cite web|url=https://www.nhc.noaa.gov/aboututc.shtml|title=What is UTC or GMT Time?|website=National Hurricane Center |access-date=August 22, 2018|archive-date=August 22, 2018|archive-url=https://web.archive.org/web/20180822150019/https://www.nhc.noaa.gov/aboututc.shtml|url-status=live}}</ref>

=== Abbreviations ===
{{Main|List of time zone abbreviations}}

Time zones are often represented by alphabetic abbreviations such as "EST", "WST", and "CST", but these are not part of the international time and date standard [[ISO 8601#Time zone designators|ISO 8601]]. Such designations can be ambiguous; for example, "CST" can mean (North American) [[Central Standard Time]] (UTC−06:00), [[Cuba Standard Time]] (UTC−05:00) and [[China Standard Time]] (UTC+08:00), and it is also a widely used variant of ACST ([[Australian Central Standard Time]], UTC+09:30).<ref>"[https://www.timeanddate.com/time/zones/ Time Zone Abbreviations – Worldwide List]", Timeanddate.com. {{Webarchive|url=https://web.archive.org/web/20180821101900/https://www.timeanddate.com/time/zones/ |date=August 21, 2018 }}.</ref>