Timezone Converter

1. Select a date and time using the date-time picker.
2. Choose the source ("From") timezone from the dropdown.
3. Choose the target ("To") timezone from the dropdown.
4. The converted time is displayed instantly in multiple formats.
5. Use the swap button to quickly reverse the conversion direction.
6. Check the World Clock section to see the current time in major cities worldwide.

What is Timezone Conversion?

Timezone conversion calculates the equivalent local time in one timezone given a time in another timezone. The world is divided into time zones that are generally offset from Coordinated Universal Time (UTC) by whole hours, though some regions use 30-minute or even 45-minute offsets. Many areas also observe Daylight Saving Time (DST), which shifts the local clock forward by one hour during warmer months. This tool handles all of these cases automatically using the IANA timezone database built into modern browsers.

How Timezone Conversion Works

The tool first determines the UTC offset for both the source and target timezones at the specific date and time you provide. The offset can change throughout the year due to Daylight Saving Time transitions, so the date matters. The time is converted to UTC by subtracting the source offset, then converted to the target timezone by adding the target offset. This tool uses IANA timezone identifiers (like America/New_York and Asia/Tokyo) rather than abbreviations (like EST or JST), because abbreviations can be ambiguous. For example, CST can refer to Central Standard Time (US), China Standard Time, or Cuba Standard Time.

Common Use Cases

• Scheduling meetings across international teams
• Coordinating project deadlines across timezones
• Converting event times for global audiences
• Planning international travel and flight connections
• Debugging timezone-related issues in applications
• Understanding server log timestamps from different regions

Daylight Saving Time Complications

DST creates two tricky situations each year. In spring, when clocks jump forward, there is a "gap" hour that does not exist. For example, 2:30 AM does not occur on the day US clocks spring forward from 2:00 AM to 3:00 AM. In fall, when clocks fall back, there is an "overlap" hour where the same local time occurs twice. Not all countries observe DST, and those that do may start and end it on different dates. The IANA timezone database tracks all of these rules historically, so this tool provides accurate conversions for any past, present, or future date.

For date formatting, try the ISO Date Formatter. For Unix timestamps, use the Unix Timestamp Converter. To calculate time between dates, see the Date Difference Calculator.