This is a list of time zones, sorted by time offsets from Coordinated Universal Time (UTC). Countries and regions observing the respective time zones are listed under it. This only gives current offsets. For more detailed and historic information, these zones must be divided. One list that does so is the list of tz database time zones. Also see a helpful map (which is not necessarily completely up to date).
The letter after the time zone offset is that used in nautical time. The dagger symbol (†) indicates the usage of a nautical time zone letter outside of the standard definition of that time zone.
Some zones north-south of each other in the mid Pacific differ by 24 hours in time: they have the same time of day but differ by a full day. The two extreme time zones on Earth (both in the mid Pacific) differ by 26 hours. A particular day starts earlier in countries with a more positive UTC offset. Thus the first occurrence of a date will be in UTC+14 and the last of the same date in UTC−12. This gives the interesting feature that during one hour each day there are three different dates in use on land around the world, e.g. at 10:30 UTC Monday it is already Tuesday in the Line Islands (UTC+14; local time 00:30) while it is Sunday in American Samoa (UTC−11; local time 23:30).
Time zone abbreviations are almost always customary, not legal — those listed here only exist in English and are somewhat arbitrary. English time zone names below generally only apply to English-speaking areas.
Western Australia began a three-year trial of summer (daylight saving) time on December 3, 2006. Daylight saving time was used from October through March, with the late start in 2006 due to late passage of the relevant legislation. A referendum held on May 19, 2009 resulted in a majority vote against daylight saving, which is therefore not currently used in WA.
The whole of the People's Republic of China has the same time, which makes this time zone exceptionally wide. In the extreme west of China the sun is at its highest at 15:00, in the extreme east at 11:00. It also means that on the short (76 km) frontier with Afghanistan, the official time change is 3 hours and 30 minutes. The two western autonomous regions of China, Xinjiang and Tibet, were in UTC+6 during the Republic era (1912–1949), but were moved to UTC+8 after the founding of the People's Republic of China in 1949. Today, residents of the two autonomous regions do everything 2 hours late. For example, lunch is at 14:00 and business hours end around 19:00.
The more populous Peninsular Malaysia is geographically in UTC+7, but changed to UTC+8 in 1982 to follow that of Malaysian Borneo (which makes up only 20% of total population), so that the whole country lies in the same time zone.