universal time
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Universal time is used by pilots to coordinate flights across different time zones.
Definition
Noun: - Coordinated Universal Time (UTC): The primary time standard by which the world regulates clocks and time. It is effectively the modern successor to Greenwich Mean Time (GMT). - Greenwich Mean Time (GMT): The mean solar time at the Royal Observatory in Greenwich, London, historically defined as the time at the 0° longitude meridian. It is often used interchangeably with UTC in casual contexts.
Usage
- Universal Time (UT) is the basis for civil time worldwide. Time zones are defined as offsets from UT.
- It is used in scientific contexts, aviation, computing, and international communications to avoid confusion between time zones.
Examples
Advanced Usage
- UT0: Universal Time determined by astronomical observations at a specific observatory.
- UT1: A more precise form of Universal Time, which accounts for the Earth's irregular rotation by incorporating polar motion. It is the version used in celestial navigation.
- UTC: The time standard commonly used across the world. It is kept within 0.9 seconds of UT1 by the occasional addition of leap seconds.
Variants and Related Words
- Greenwich Mean Time (GMT): Often used synonymously with UT/UTC, though technically GMT is now a time zone, while UTC is the time standard.
- Zulu Time (Z): The phonetic alphabet term for UTC, commonly used in military and aviation communications (e.g., "The operation commences at 1200Z").
- World Time: A general term for a unified timekeeping system.
Synonyms
- Coordinated Universal Time (UTC)
- Greenwich Mean Time (GMT) (in common usage)
- Zulu Time
Related Phrases
- UT Offset: The difference in hours and minutes from Universal Time.
- Tokyo has a UT offset of +9 hours.
- Synchronized to UT: Adjusted to match Universal Time.
- The network servers are synchronized to UT.
Universal time is used by pilots to coordinate flights across different time zones.
Noun
- the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere