What Are Time Zones?
Time zones are regions of Earth that have adopted the same standard time. The world is divided into 24 primary time zones, each generally 15 degrees of longitude apart, corresponding to one hour of time difference.
History of Time Zones
Before time zones were established, each city kept its own local time based on the sun's position. This became problematic with the advent of railways and telecommunications. In 1884, the International Meridian Conference established the Greenwich Meridian as the prime meridian, creating the basis for our modern time zone system.
How Time Zones Work
Time zones are measured as offsets from Coordinated Universal Time (UTC). For example, New York is UTC-5, meaning it is 5 hours behind UTC. India is UTC+5:30, which is 5 hours and 30 minutes ahead of UTC.
Daylight Saving Time
Many countries adjust their clocks forward by one hour during summer months to make better use of daylight. This practice, known as Daylight Saving Time (DST), can complicate time zone calculations.