Time Zone Converter
Convert a date and time between major world time zones with daylight-saving adjustments.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Converted time
Thursday, January 1, 2026 at 4:00:00 AM EST
UTC / ISO 8601
2026-01-01T09:00:00.000Z
What this tool does
Interprets a wall-clock date and time in one selected IANA time zone, resolves it to a UTC instant, and formats that instant in another zone. It also displays the corresponding ISO 8601 UTC timestamp.
How to use it
Choose a local date and time, source zone, and destination zone from the 18 available options. Results update immediately; Reset returns to 1 January 2026 at 12:00 from Europe/Istanbul to America/New_York.
Worked example
For 2026-01-01 12:00 in Europe/Istanbul, the resolved UTC instant is 2026-01-01T09:00:00.000Z. In America/New_York that instant is 04:00 on the same date because the zones are eight hours apart then.
Time-zone and DST handling
The converter uses browser Intl.DateTimeFormat data and named zones rather than fixed offsets, so ordinary daylight-saving changes are reflected for the selected date. The destination text uses the browser's display locale.
Available zones
The selector contains UTC plus 17 named zones across Europe, the Americas, Asia, Australia, and New Zealand. Arbitrary IANA identifiers, abbreviations such as EST, and custom numeric offsets cannot be entered.
Limitations
During a daylight-saving transition, some local times occur twice or do not exist. The three-pass resolver chooses an instant but does not warn about ambiguity or gaps; verify transition-sensitive scheduling with an authoritative source.
Standards and privacy
The UTC output uses Date.toISOString and the conversion depends on the browser's IANA/Intl data, which can vary by runtime version. Everything is computed locally and entered dates are not uploaded.
Frequently Asked Questions
- Does the converter account for daylight-saving time?
- Yes for ordinary dates: it uses named IANA zones and the browser's Intl time-zone data, so the offset is selected for the date rather than treated as a fixed number.
- Why can a DST transition time be ambiguous?
- When clocks move back a local time can occur twice, and when they move forward a time can be skipped. This tool does not ask which occurrence you intend, so verify critical schedules.
- Can I enter any time-zone name or abbreviation?
- No. You can choose from the 18 zones in the selector; arbitrary IANA names, abbreviations such as EST, and custom UTC offsets are not accepted.