Does it handle daylight saving time?

Yes. The converter uses your browser's native Intl.DateTimeFormat with IANA zones, so DST is applied based on the specific instant rather than a fixed offset. This is correct even on transition days.

What format does the source zone use?

IANA zone names like `America/New_York`, `Europe/London`, `Asia/Tokyo`, `Australia/Sydney`. Abbreviations like "EST" are deliberately not used because they are ambiguous (EST can mean US Eastern or Australian Eastern Standard).

What happens on a DST "spring forward" gap?

If you pick a wall-clock time that does not exist in the source zone (e.g. 02:30 on a spring-forward Sunday), the underlying Date API normalises it forward by an hour. The destination time will reflect that normalisation.

Can I convert multiple destinations at once?

Yes. Pick as many destination zones as you need; the tool produces one row per destination so you can compare meeting times across a whole team in one screen.

Does the tool log my data?

No. Conversion happens entirely in your browser. Nothing is uploaded or stored between sessions.

Time Zone Converter

Convert wall-clock times between any IANA time zones, DST-aware.

Written by Golam Rabbani, Founder & Lead Engineer

This interactive tool requires JavaScript. Read the formula and worked example below; you can compute the result by hand.

How to use this time zone converter

Pick the source IANA time zone (e.g. America/New_York).
Enter the date and time as it appears in that source zone.
Pick one or more destination IANA zones.
Press Convert to see the matching wall-clock time in each destination.
Use Copy to grab any line, or Reset to start over.

About this time zone converter

The time zone converter takes a wall-clock time in one IANA zone and shows the matching wall-clock time in any other IANA zone, automatically applying daylight saving time (DST) where it is in force for that specific instant. It is the calculation you actually want when scheduling a call across continents — not the naive "add five hours" arithmetic that breaks twice a year.

Under the hood the tool combines the source date/time with the source IANA zone to produce an absolute UTC instant, then formats that instant in each destination zone using the browser's native Intl.DateTimeFormat. Because Intl carries the full IANA database (the same `zoneinfo` data your operating system uses), DST transitions, historical offset changes, and edge cases like Samoa's 2011 dateline shift are all handled correctly. We assume your browser's tz data is current; almost all modern browsers update it automatically.

For example, a meeting at 09:00 in `America/New_York` on 2024-11-04 (the day after US DST ends) maps to 14:00 `Europe/London`, 19:30 `Asia/Kolkata`, and 03:00 the next day in `Australia/Sydney`. The same wall-clock meeting one week earlier maps to 13:00 London — exactly the kind of off-by-one DST trap the tool avoids.

FAQ

Does it handle daylight saving time?: Yes. The converter uses your browser's native Intl.DateTimeFormat with IANA zones, so DST is applied based on the specific instant rather than a fixed offset. This is correct even on transition days.
What format does the source zone use?: IANA zone names like `America/New_York`, `Europe/London`, `Asia/Tokyo`, `Australia/Sydney`. Abbreviations like "EST" are deliberately not used because they are ambiguous (EST can mean US Eastern or Australian Eastern Standard).
What happens on a DST "spring forward" gap?: If you pick a wall-clock time that does not exist in the source zone (e.g. 02:30 on a spring-forward Sunday), the underlying Date API normalises it forward by an hour. The destination time will reflect that normalisation.
Can I convert multiple destinations at once?: Yes. Pick as many destination zones as you need; the tool produces one row per destination so you can compare meeting times across a whole team in one screen.
Does the tool log my data?: No. Conversion happens entirely in your browser. Nothing is uploaded or stored between sessions.