Final answer:
METARs (Meteorological Aerodrome Reports) use Coordinated Universal Time (UTC), also referred to as Zulu (Z) time, based on a 24-hour time scale for global operations synchronization.
Step-by-step explanation:
The time given in METARs (Meteorological Aerodrome Reports) is Coordinated Universal Time (UTC) which is also known as Zulu (Z) time. This is the time at 0 degrees longitude and the prime meridian located in Greenwich, England. UTC, which operates on a 24-hour time scale, is essential for global operations such as military activities, international radio broadcasts, air traffic control, and aviation to ensure coordinated and universal timing across different time zones. This allows for coordination across different time zones and eliminates confusion caused by using different time conventions in different regions.