What Is a Time Zone?

A time zone is a region of the earth where all the clocks are set to the same time. This is done for two purposes: to ensure that “noon” doesn’t occur in the middle of the night, and to support legal/business/social needs for those in the same time zone.

History of Time Zones

The need for time zones was a factor of the world becoming more connected. As railroads made longer-distance travel possible, and as train schedules needed to be published, railroad companies started to keep their own time to set the clocks at the station.

By 1900, most of the world recognized some standard time zone, but most were relative to the time at a local observatory. By 1929, the majority of the world had adopted time zones that were measured as an offset from the time in Greenwich, England (Greenwich Mean Time, or GMT).

Daylight Saving Time

Several parts of the world, primarily North America and Europe, advance the clocks during summer (typically one hour, though exceptions do exist). The original proponents for daylight saving time claimed a number of projected benefits from increasing the number of evening hours with daylight during the summer months.