Timezone Converter
Convert a date and time between any two world timezones, including DST.
2026-10-18 22:46:00
UTC · GMT+0
2026-10-18 22:46:00
UTC · GMT+0
UTC: 2026-10-18T22:46:00.000Z
How to use
- Pick the source timezone — defaults to your local zone.
- Pick the destination timezone.
- Enter the date and time, or click Now.
- Read both sides and copy the result.
About this tool
ShowHide
Pick a source and a target zone, enter a date and time, and read the equivalent local time on the other side along with the matching UTC instant. The zone list comes from the browser's own IANA database, so it covers every region your system knows rather than a hand-written list of abbreviations, and each side shows its current offset — the quickest way to see whether a zone is on summer time on the date you chose. Two moments a year deserve care: an hour that daylight saving skips does not exist locally and is resolved to the adjacent instant, and the repeated hour after a fall-back maps to one of its two possible instants. When a meeting sits inside that hour, check the offset shown next to the result.
Frequently asked questions
How is DST handled?
The browser's IANA timezone data is used (via Intl.DateTimeFormat), so transitions like spring-forward and fall-back are accurate per region.
Why do I see hundreds of timezones?
IANA lists one zone per region that has had a unique offset history. If your country isn't visible, try its capital — e.g. Asia/Seoul, Europe/London.
What about UTC offsets like +09:00?
Each card shows the offset (like GMT+9) right below the time. The bottom row shows the matching ISO 8601 UTC string.
Is my data saved?
Source and destination zones are kept in your browser's local storage so the form remembers your last choice — nothing is uploaded.
Why should I schedule with a zone name rather than an offset?
Because an offset is only true on a particular date. Asia/Seoul is always Seoul; GMT+9 is Seoul and Tokyo all year but not Sydney, and any zone that observes daylight saving changes its offset twice a year. Store the zone and let the offset be derived.
What happens to a time that daylight saving skips?
It does not exist locally — the clock jumps straight over that hour — so it resolves to the adjacent instant instead. The repeated hour after the autumn change has the opposite problem: it happens twice and maps to one of the two. Check the offset shown beside the result when a meeting falls in either.
Guides on this topic
- Working with Time Zones and Unix Timestamps Without BugsWhy time is so hard to get right in software — UTC, Unix timestamps, time zones and DST — and a small set of rules that prevent the most common date-handling bugs.
- How Cron Schedules Actually WorkThe five cron fields and their syntax, the day-of-month/day-of-week rule almost everyone gets wrong, what daylight saving does to a nightly job, and how to design schedules that survive restarts.
- Counting Days: Date Math That Trips People UpInclusive versus exclusive counts, adding a month to 31 January, leap years, 29 February birthdays, business days and days that are not 24 hours.
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