The invention of railroads ushered in a new era of land travel, and forever changed the way humans perceive time.

It takes 24 hours for the Earth to rotate once on its axis. We split the globe into time zones using imaginary lines called meridians. They run from the North Pole to the South Pole, crossing ...

Coordinated Lunar Time will help with precise space-travel calculations. But first, NASA has to figure out how to make it ...