Definition

1. Noun:
   • The standard time at the prime meridian: Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, located at the 0° longitude meridian. It serves as a global time reference point.
   • A universal time standard: Historically, GMT was the basis for civil time and time zones around the world, though it has largely been superseded by Coordinated Universal Time (UTC) for precise scientific purposes.

Usage Examples

• Noun:
  • The conference call is scheduled for 14:00 Greenwich Mean Time.
  • Before traveling, check the time difference between your local time and Greenwich Mean Time.

Advanced Usage

• "GMT" as an abbreviation: The term is almost universally abbreviated to "GMT" in technical, aviation, and maritime contexts.
  • The log entry must be recorded in GMT.
• Historical Context: GMT is often referenced in historical texts and discussions about the establishment of international time zones.
  • The global system of time zones was developed based on Greenwich Mean Time.

Variants and Related Words

• Coordinated Universal Time (UTC): The primary time standard by which the world regulates clocks and time. While often used interchangeably with GMT in casual contexts, UTC is a more precise standard based on atomic clocks.
• Universal Time (UT): A time standard based on the rotation of the Earth, closely related to GMT.
• Zulu Time (Z): A term used in military and aviation for UTC/GMT, where 'Z' stands for Zulu, the phonetic alphabet code for 'Z'.

Synonyms

• Universal Time (UT): In many astronomical and navigational contexts.
• Zulu Time: Specifically in military and aviation communications.

Related Phrases

• "GMT +/- [number]": Used to indicate a time zone offset from GMT.
  • The country operates on GMT+8.
• "Greenwich Time": A less formal, shortened version of the term.
  • Set your watch to Greenwich Time.

Noun

1. the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere