OTHER · TIMEZONE CONVERTER
Timezone Converter Calculator
Convert times between timezones — Eastern, Pacific, GMT, Tokyo, Sydney, and 20+ more — with correct DST handling for any date.
About This Calculator
Convert a date between any two of the world's most common timezones — from New York to Tokyo, London to Sydney, or UTC to any local time — with accurate Daylight Saving Time (DST) handling built in. Pick a date, pick your zones, and see the result instantly.
How It Works
Select a date, a source timezone, and a target timezone. The converter shows the time in both zones at noon UTC on that date, using your browser's built-in timezone database (IANA) for DST-correct results. No UTC-offset shortcuts — the same date can have a different offset depending on whether DST is in effect.
The Formula
The converter passes the selected date (as a UTC noon timestamp) to the browser's Intl.DateTimeFormat API with each IANA timezone name. The API handles all DST transitions automatically, including historical rule changes for each zone.
Frequently Asked Questions
- Why does my timezone show different offsets in winter vs summer?
- Most North American and European zones observe Daylight Saving Time (DST), shifting their UTC offset by +1 hour in summer. For example, Eastern Time is UTC−5 (EST) in winter and UTC−4 (EDT) in summer. This converter handles those shifts automatically for the date you select.
- What does UTC mean and is it the same as GMT?
- UTC (Coordinated Universal Time) is the world's primary time standard — it never observes DST. GMT (Greenwich Mean Time) is the same offset (UTC+0) and the two are interchangeable for everyday use, though they differ technically at the microsecond level.
- Why is India's timezone UTC+5:30 instead of a whole hour?
- Some countries chose half-hour or 45-minute offsets from UTC for geographic or political reasons. India Standard Time (IST) is UTC+5:30; Nepal is UTC+5:45. This converter handles all these non-integer offsets correctly.
- Which timezone should I use for New York vs Eastern Time?
- They are the same — "Eastern Time" covers New York, Toronto, Miami, and all US East Coast cities. The IANA name is America/New_York. This converter uses IANA names internally but shows them with familiar labels like "Eastern Time (ET)".