词条 时区
描述: 时区是指使用统一标准时间的一个区域。我们对时间的度量与地球自转有关。特别是正午时刻，与太阳在天空中的最高位置有关。当地正午时间在很大程度上取决于经度：位于东边的观察者会比西边的观察者更早看到太阳升起并到达正午。位于同一经度的所有地点都有相同的当地正午时刻，因此原则上，我们可以为所有这些地点定义一个共同的时间标准。实际上，统一时间是为一定经度范围、一个国家或一个国家的一个地区定义的。对于大多数地点而言，当地正午接近该时区的官方正午，但略早于或略晚。在这种情况下，官方时间的差异几乎总是整数小时（尽管有些特定的时区偏离了这一情况，例如相差半小时）。
相关词条
用其他语言查看该词条
词条和定义状态： 该术语的英文原始定义已通过天文研究人员和教师的审核 该术语及其定义的译文仍待审核
OAE多语言词汇表是由国际天文学联合会（IAU） 天文教育办公室（OAE） 和 国际天文学联合会（IAU） 天文推广办公室（OAO）合作的项目。. 术语和定义由 OAE中心, OAE 国家天文教育协调员（NAECs） 以及其他志愿者共同选择、撰写和审阅。您可以在 找到完整的致谢列表。所有词汇表术语及其定义均根据 Creative Commons CC BY-4.0许可证发布 且版权归属于 “IAU OAE”。
如果您发现此词汇术语或定义中的事实或翻译错误， 请向 发邮件 联系.
其他语言版本
- 阿拉伯语: المنطقة الزمنية
- 德语: Zeitzone
- 英语: Time Zone
- 西班牙语: Huso horario
- 法语: Fuseau horaire
- 意大利语: Fuso orario
- 日语: タイムゾーン (外部链接)
- 巴西葡萄牙语: Fuso horário
- 繁体中文: 時區
相关媒体
Map of de-facto time zones on Earth
图注： Due to the Earth's spherical shape and its rotation around its own axis, local noon – the moment in time when, for an observer at a specific geographic location, the Sun reaches its highest position in the sky varies with longitude. That is why a time coordinate, such as Universal Time (UT or UTC), might be of advantage for specifying moments in time in a unified way. But a global time coordinate will be out of synch with the local day-night rhythm in most locations on Earth. A compromise is to divide Earth into zones each comprising 15 degrees of longitude, and in each zone define time as UTC plus or minus an integer number of hours, with the offset chosen so as to make time match as closely with local time at the middle longitude of the time zone. In practice, political considerations have altered the time zone boundaries somewhat. When a country straddles several time zones, it is not uncommon for the country's government to choose one of those time zones to define the country's official time.
This map, originally created by the CIA and updated by several Wikimedia Commons users, shows the current definitions of the world's time zones. The IAU OAE is not the original author of this map. The designations employed and the presentation of the material on this maps do not imply the expression of any opinion whatsoever on the part of the IAU or the IAU OAE concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
来源： Wikimedia Users UnaitxuGV, Heitordp and others based on a map created by the U.S. Central Intelligence Agency (CIA)
来源链接
License: PD 公共领域 图标
相关图表
International Date Line
图注： The International Date Line (shown here as a solid line) is a specific meridian which roughly follows the meridian of longitude 180°. The International Date Line passes north–south between Russia and Alaska, through the Pacific Ocean including parts of Micronesia and Polynesia, and to the east of Australia/New Zealand before reaching the South Pole on Antarctica. The International Date Line marks the boundary where calendar dates change by one. Therefore, regions to the west of the International Date line are one calendar day ahead of regions to the east.
The International Date Line does not always exactly follow the meridian of longitude 180°. This is partly to stop some territory of a country falling on the other side of the International Date Line than the rest of that country (the Aleutian Islands in the United States being a good example). Some countries also choose which side of the International Date Line they lie on. Samoa changed which side of the date line it lay on in 2011. At this point the International Date Line was moved to lie to the east of Samoa having previously passed to the west of Samoa.
On the opposite side of the world the dashed line marks the prime meridian (the meridian of longitude 0°). This is a line that passes through the Royal Greenwich Observatory in the UK. All time zones are measure relative to Universal Time which is the zero point for all timezones. The time zones marked at the top of the diagram are the timezones in the shaded regions excluding the effects of daylight savings time.
来源： Maria Cristina Fortuna/IAU OAE
