Time Zone Converter & World Clock

In our interconnected world, knowing "what time it is" isn't just about glancing at your wrist. It involves understanding the complex web of Time Zones, Coordinated Universal Time (UTC), and the often-confusing Daylight Saving Time (DST). Whether you are scheduling a business call from New York to Mumbai or planning a trip to Tokyo, accuracy is key.

What is a Time Zone?

Ideally, the sun would be at its highest point at noon everywhere. However, since the Earth rotates, the sun cannot be overhead everywhere at once. To solve this, the world is divided into 24 standard time zones, each roughly 15 degrees of longitude wide.

Before standard time zones were established in the late 19th century, cities kept their own "local mean time" based on the sun. This caused chaos for railroad schedules. In 1884, the International Meridian Conference established the Prime Meridian in Greenwich, London, as the starting point (0 degrees longitude) for global timekeeping.

UTC vs. GMT: What's the Difference?

You often hear these terms used interchangeably, but there is a technical difference:

Daylight Saving Time (DST) Explained

Daylight Saving Time is the practice of advancing clocks (usually by one hour) during warmer months so that darkness falls later each day according to the clock.

The Impact: This means the time difference between two cities can change during the year. For example, the difference between New York (EST) and London (GMT) is normally 5 hours. However, since the US and UK start DST on different dates in March, the gap narrows to 4 hours for a few weeks!

Major Global Business Time Zones

Fun Time Zone Facts

• China's Single Zone: Despite spanning a width comparable to the continental US (which has 4 zones), all of China operates on Beijing Time (UTC+8). This means in western China, the sun rises as late as 10 AM!
• Half-Hour Zones: Not all offsets are whole hours. India (IST) is UTC+5:30, Nepal is UTC+5:45, and parts of Australia use half-hour offsets.
• France holds the record: Including its overseas territories, France has the most time zones of any country (12 zones), beating the US and Russia.
• International Date Line (IDL): Located roughly at 180° longitude, crossing this line means you jump forward or backward an entire day.

Frequently Asked Questions