Timezone Converter

Convert Time Across Timezones

This timezone converter lets you see the current time in any set of IANA timezones, or pick a specific date and time to compare across zones. DST rules are applied automatically based on the date. Add and remove timezones freely, share your setup with a permalink, or swap source and target to reverse the comparison.

What is a Timezone Converter?

A timezone converter translates a date and time from one IANA timezone to another, accounting for daylight saving time rules and historical offset changes. Timezones are identified by strings like America/New_York or Asia/Tokyo, which encode the full DST transition history for that location. The browser’s Intl API handles the conversion using the IANA timezone database. This is essential for scheduling meetings across distributed teams, coordinating deployments, understanding log timestamps from servers in different regions, and avoiding the common mistake of assuming a fixed UTC offset applies year-round.

How to Use

1. Pick your source timezone by typing in the search field and selecting from the dropdown
2. Set the time using the date and time inputs, or click Now for live mode
3. Add timezones to compare by clicking Add Timezone and searching for a region or city
4. Read the results for each target: local time, date, abbreviation, and UTC offset
5. Remove or swap timezones using the X button or the Swap button

How It Works

Timezones are defined by IANA (Internet Assigned Numbers Authority), also known as the Olson database. Every timezone entry has a unique identifier following the Area/Location convention: America/New_York, Europe/London, Asia/Tokyo. These identifiers encode historical timezone rules, DST transition dates, and standard vs daylight offsets.

The browser’s Intl API handles the actual conversion. Intl.DateTimeFormat with a timeZone option converts any Date value to the target timezone, accounting for DST automatically. The abbreviation (EST, EDT, JST, IST, etc.) and the UTC offset (+05:30, -04:00, etc.) are extracted from the same API to give you a complete picture of what each timezone means at that specific moment.

Common Timezone Abbreviations

For a focused US coast-to-coast comparison, see the EST to PST converter. Scheduling tasks across timezones? The Cron Expression Builder helps you define schedules, and the Unix Timestamp Converter shows the epoch time for any moment.

DST Gotchas

Daylight saving time is not observed uniformly. The US and Europe start and end DST on different dates. Australia has regions that observe DST and regions that do not. Some countries have abolished DST entirely. The IANA database tracks all these rules, which is why using IANA identifiers is more reliable than UTC offset alone. An offset of +05:30 could be India Standard Time year round or Nepal Time (which uses +05:45). The identifier tells you the rules, not just the current offset.

FAQs

Q: Why use IANA timezone identifiers instead of UTC offsets? A: Offsets change with DST. IANA identifiers like America/New_York encode the full DST rules, so the same identifier gives you -05:00 in winter and -04:00 in summer automatically.

Q: What happens if I select an invalid date? A: The converter falls back to the current time. Invalid dates are caught and ignored.

Q: Can I share my timezone comparison? A: Yes. Click the Share button to copy a permalink with your source timezone, target timezones, and date/time encoded. Paste it to share the exact view.