Time Zone Converter — Free Online
Convert time between any two world timezones with full Daylight Saving Time support. Uses the IANA timezone database for DST-accurate results across all 400+ timezones.
How to Use the Time Zone Converter
- Select the date using the date picker — DST rules are applied for that specific date
- Enter the time you want to convert in the "Time" field
- Choose the source timezone from the "From Timezone" dropdown
- Choose the target timezone from the "To Timezone" dropdown
- Click "Convert Time" — the result shows the converted date, time, UTC offset, and DST status
How the Time Zone Converter Works — The Formula
The converter uses the IANA timezone database (via Luxon) to apply the correct UTC offset for the given date and timezone. The conversion first normalizes the input time to UTC, then applies the target timezone's offset — including any active DST adjustment.
UTC Time = Input Time − Source UTC Offset (with DST)
Output Time = UTC Time + Target UTC Offset (with DST)
DST Rule: applied per IANA database for exact date
Example: New York is UTC-5 (EST) in winter, UTC-4 (EDT) in summer
Formula validated by Vipul Jaganiya, Computer Science expert in Calendar Mathematics and Timezone Engineering.
Real-World Examples
| From | To | Input | Output |
|---|---|---|---|
| UTC | Asia/Kolkata | 2026-05-26 12:00 | 2026-05-26 17:30 IST |
| America/New_York | Europe/London | 2026-06-01 09:00 | 2026-06-01 14:00 BST |
| Asia/Tokyo | America/Los_Angeles | 2026-05-26 09:00 | 2026-05-25 17:00 PDT |
| Europe/Berlin | Asia/Singapore | 2026-01-15 18:00 | 2026-01-16 01:00 SGT |