Time Zone Converter

What is a Time Zone?

A time zone is a region of the Earth that observes a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions rather than strictly following longitude, because it is convenient for areas in frequent communication to keep the same time.

The world is divided into roughly 24 time zones, each approximately 15 degrees of longitude wide. However, the actual boundaries are irregular and determined by political and geographical considerations. Some countries span multiple time zones (like the United States, Russia, and Australia), while others use a single time zone across their entire territory (like China, which uses a single time zone despite spanning five geographical zones).

Daylight Saving Time (DST) adds another layer of complexity, as many regions advance their clocks by one hour during summer months. Our converter uses the IANA time zone database, which automatically accounts for DST transitions, so you always get accurate conversions regardless of the time of year.

How to Use This Tool

Select the source time zone from the "From" dropdown and the target time zone from the "To" dropdown. The source defaults to your browser's detected time zone and the target defaults to UTC. Enter the date and time you want to convert using the date and time picker.

The conversion happens in real time as you change any input. The result shows both the source time and the converted time in a clear, easy-to-read format. You can also see the current time in both zones at the top of the page, which updates every second.

Use the swap button between the two time zone dropdowns to quickly reverse the conversion direction. This is useful when you need to convert times back and forth between two zones.

Common Time Zones

Our converter includes 29 major time zones covering cities and regions around the world. Here are some of the most commonly used:

• UTC -- Coordinated Universal Time, the reference point for all time zones. Used in aviation, computing, and international communication.
• ET (Eastern Time) -- New York time zone, used by the US East Coast. Important for financial markets and business operations.
• PT (Pacific Time) -- Los Angeles time zone, used by the US West Coast. Home to Silicon Valley and Hollywood.
• GMT/BST -- London time zone, the historical basis for civil timekeeping. Greenwich Mean Time in winter, British Summer Time in summer.
• CET -- Central European Time, used by Paris, Berlin, and most of continental Europe.
• JST-- Japan Standard Time, 9 hours ahead of UTC. Used in one of the world's largest economies.
• AEST -- Australian Eastern Standard Time, used by Sydney and the most populated parts of Australia.