Greenwich Mean Time (GMT) is the mean solar time-based at the Royal Observatory in Greenwich, London, and it's the basis on which all other zones are measured worldwide. A GMT watch will always have a supplementary hand or rotating bezel that tells a second time zone, which is very helpful for travelers and those coordinating across different time zones. GMT watches are, therefore, popular among pilots and global travelers.
The watch simply gives an easy way to track multiple time zones simultaneously. The function can add practical value and a hint of adventure, especially for someone with a global lifestyle.
