Live Coordinated Universal Time beside your local clock, with the offset drawn so the gap is obvious.
Δ +00:00 · syncing
People still type GMT when they mean the scientific reference. The names overlap in casual speech. The definitions do not.
UTC is the civil time scale kept by laboratories using atomic clocks, with rare leap-second fixes so clocks stay near Earth rotation. GMT started as mean solar time at Greenwich. The UK still uses the GMT label in winter for the UTC+00:00 civil zone. For logging, APIs, aviation flight plans, and almost every modern protocol, write UTC.
| Topic | UTC | GMT |
|---|---|---|
| What it is | Time scale (atomic, coordinated) | Historical mean solar time / UK winter zone name |
| Daylight saving | Never shifts for DST | UK switches away from the GMT label in summer (BST) |
| Safe stamp for software | Yes. Prefer …Z or explicit offset | Risky. Many systems treat GMT as a synonym, some do not |
| On this page | Left panel + ISO / Unix chips | Not shown as a separate clock |
If a vendor email says “GMT” but the payload uses a Z suffix, trust the payload. Labels lie more often than ISO strings.
This viewer never asks a geolocation API. Your browser already knows an IANA zone name such as Asia/Karachi or America/New_York.
Each second the page reads one Date instant, formats the left panel in UTC, formats the right panel in your zone, then measures the minute gap with getTimezoneOffset(). The coral mark on the rail is that gap mapped between −12h and +14h.
DST is already baked into the browser zone rules. When New York flips from UTC−05:00 to UTC−04:00, the local panel and the rail move with the next tick. You do not flip a switch here.
Copy buttons grab the strings teams paste into tickets: readable UTC, local wall time, or a full ISO-8601 value ending in Z. Share link copies the page URL so a teammate opens the same live instrument, not a frozen screenshot.
Need a conversion for a city you are not sitting in? Use the Timezone Converter. This page stays a live reference, not a full atlas.
UTC is the right storage format for almost every backend. Showing raw UTC to every end user is a different question.
14:00Z into a retail checkout creates support tickets.GMT in RFC 822 headers. Parse the offset. Do not assume British winter rules.We recommend storing UTC in databases and converting at the edge of the UI. Mixing “local write, UTC read” is how duplicate night jobs appear after a DST weekend.
For epoch math, pair this view with the Unix Timestamp Converter. For “what does my wall clock say right now” with neighbors, open What Time Is Now.
Copy patterns teams paste into tickets every day.
2026-07-20T14:32:08Z release=web@3.4.1 status=okStore the deploy in UTC. Let dashboards convert for whoever is on call.
Kickoff: 2026-07-20 14:30 UTC (check your local panel above for the wall-clock time)One UTC line beats three conflicting city times in a Slack thread.
"created_at": "2026-07-20T14:32:08.000Z"Keep the Z. Silent local offsets in JSON are how duplicate rows appear after DST weekends.
Short answers about this live viewer, offsets, and accuracy limits.
Your browser. Every tick formats one local Date object into UTC and into your IANA zone. No time API round trip.
Offsets push the wall clock across midnight. Someone at UTC+14 already sits on tomorrow while UTC remains on today. The delta line under the rail calls this out.
No separate GMT panel. For software stamps, use the UTC panel and the ISO chip. GMT remains a UK winter zone label, not the scientific scale.
As accurate as your device clock. NTP drift of a few hundred milliseconds is common on laptops. Fine for meetings and logs. Not fine for stopwatch lab work.
No. Zone detection and formatting stay in the page. Copy and share only put text on your clipboard or build a link to this URL.
