A comprehensive one-page guide to how timezones work, why they exist, and where you can explore each one.
Timezones are regions of the Earth that share the same standard time. They exist because the planet rotates 360° every 24 hours, meaning different parts of the world experience daylight at different times.
To keep clocks aligned with solar time, the world is divided into offset-based regions, generally spaced in increments of one hour from Coordinated Universal Time (UTC). Some timezones differ by 30 or 45 minutes.
Before standardized time, local solar noon determined the clock in each town. This became chaotic with the rise of railroads, telecommunication, and international commerce. In 1884, the International Meridian Conference established the global timezone system we use today.
Click any timezone below to view detailed information: