Glossary
Travel & Geography
International Date Line
Definition
An imaginary line running roughly along the 180th meridian in the Pacific Ocean where the calendar date changes. Traveling westward crosses to the next day; eastward to the previous day.
Related Terms
Time Zone
A region of the globe that observes a uniform standard time. The world is divided into 24 primary time zones, each offset from UTC by whole or half hours.
UTC/GMT/Zulu Time
Coordinated Universal Time (UTC), the primary time standard used in aviation worldwide. Also known as Greenwich Mean Time (GMT) or Zulu time (indicated by 'Z' suffix).
Hemisphere
Half of the Earth divided by either the equator (Northern/Southern) or the Prime Meridian (Eastern/Western). Understanding hemispheres helps with seasonal differences and route planning.