About Timezone Converter
Pick a date/time and see it across as many pinned timezones as you want. Drag the time slider to adjust the source — every pinned zone updates live. DST-aware (uses IANA tzdb). Add any zone by city or by IANA name. Useful for scheduling meetings, debugging timestamps, and remembering when your colleague is awake.
Why timezone math is hard
Scheduling across zones is the moment most calendaring software shows its age. UTC math is fine. DST adds two boundary days a year where naive offset math gives the wrong answer. The international date line adds a 26-hour gap where “Friday morning your time” is “Saturday morning theirs”. Some countries (Iran, Nepal, parts of Australia) have non-hour offsets.
A good converter outsources all of this to the IANA tzdb — the canonical database of every zone’s DST rules through history. The tool here uses the browser’s Intl API, which is backed by the same tzdb your operating system carries.
How it helps
- Drag-to-adjust. Move the source time, watch every zone update simultaneously. Pick a time that works for everyone.
- Multi-zone pin. Pin as many as you need (5+ zones for distributed teams).
- Working hours overlay. Each zone shows whether the time falls inside business hours (configurable).
- DST badge. Indicates if the zone is currently observing DST and when the next transition is.
- Permalink. URL captures the state — share a link, recipient sees the same configuration.
Common workflows
Schedule a kickoff with India, Berlin, San Francisco. Pin all three zones. Drag the slider to find a slot that lands in working hours for everyone (rare); if not, find the slot that minimizes the worst case.
Debug a “wrong timestamp” bug. Paste the timestamp, see it across UTC plus your zone. Compare to what your application displays. Mismatch flags a bug.
Plan a launch announcement. Press release embargoed at 9 AM Eastern — what is that in Tokyo, London, Sydney? Drag-and-pin gives the answer instantly.
Remember when to ping someone. Pin their zone. Glance at the converter. Now you know if your “quick question” message arrives at midnight or 11 AM.
Why a tool, not a clock app
Phones show one or two extra clocks well. Conversion-and-drag is what’s missing. This tool is the conversion-first lens — useful for meeting planning, daily standup awareness, and timestamp debugging.
Frequently asked questions
What is an IANA timezone?
America/New_York, Europe/London, Asia/Tokyo. Carries the historical DST rules so old timestamps reconstruct correctly. Prefer over EST / PST / BST abbreviations.Why use IANA names instead of UTC offsets?
America/New_York is UTC-5 in winter, UTC-4 in summer. The named zone follows the rule; a fixed offset gets the conversion wrong twice a year.Are DST shifts handled?
Intl.DateTimeFormat). DST transitions are respected including the gap (spring forward) and the overlap (fall back).Does it work across the date line?
Pacific/Auckland (UTC+13) versus America/Los_Angeles (UTC-8) — the converter handles the day shift automatically.What zones can I pin?
Can I share a meeting time?
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Last updated: 2025-01-15