Timezone Converter
Convert a date and time across major world time zones at once, with correct DST handling.
Every conversion runs locally in your browser, using its built-in timezone database — nothing you enter here is sent to a server.
For informational and educational purposes only — not professional or technical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why timezone conversion isn't just addition
A fixed UTC offset breaks twice a year in any timezone that observes daylight saving time — New York is UTC-5 in winter but UTC-4 in summer, and the switchover dates themselves have changed historically. Rather than hand-tracking those rules, this converter uses the browser's built-in Intl.DateTimeFormat, backed by the IANA time zone database that ships with every modern browser and gets updated as timezone rules change.
Frequently asked questions
Why does this need to account for daylight saving time?
DST start and end dates vary by country and even change over time by law, so a fixed UTC-offset conversion would be wrong for half the year in many timezones — this converter uses proper timezone rules, not a static offset.