UTC / GMT Time Calculator

When to use this calculator

This is a UTC/GMT-first time converter. Use it when one side of the conversion is always UTC or GMT — reading a server log timestamp, checking when a software release goes live, converting an API response to your local time, or scheduling an international meeting from a UTC reference.

UTC/GMT to Local: enter a UTC or GMT time and date, select your city, and click Convert. The result shows the equivalent local wall-clock time with daylight saving time applied for the selected date.

Local to UTC/GMT: enter your local time and date, select your city, and click Convert. The result shows the equivalent UTC or GMT time — useful when you need to express a local time as a universal reference for an API call, log entry, or broadcast announcement.

UTC vs GMT — what is the difference?

UTC (Coordinated Universal Time) became the main international time standard in 1972 and is now used as the global reference for timekeeping. UTC never observes daylight saving time and stays at offset UTC+0 year-round. All other time zones are defined as UTC plus or minus an offset.

GMT (Greenwich Mean Time) is the historical predecessor, originally based on the mean solar time at the Royal Observatory in Greenwich, England. In everyday usage — and in most software, databases, and broadcast schedules — GMT and UTC are treated as identical (both at offset 0). The difference between them is less than one second, which matters only in high-precision scientific contexts.

For any gmt time conversion or utc time calculation on this page, the result is the same whether you select UTC or GMT. The toggle simply changes the label shown in the result.

What is Zulu time?

Zulu time is UTC expressed using NATO phonetic alphabet notation. The letter “Z” (pronounced “Zulu”) appended to a time — for example, “14:00Z” or “1400Z” — means 14:00 UTC. Zulu time is standard in aviation, military operations, and international meteorology. ISO 8601 timestamps ending in “Z” (e.g. 2026-05-15T14:00:00Z) also refer to UTC.

When you encounter a Zulu time or a Z-suffixed timestamp in a log, flight schedule, or API response, enter it directly as UTC in this calculator.

Daylight saving time and UTC

UTC never changes — it is the fixed reference point. Local time zones shift by one hour when daylight saving time begins or ends. This is why the UTC offset for New York is UTC-5 (EST) in January and UTC-4 (EDT) in July. When you convert UTC to EST, you get a different answer than when you convert UTC to EDT.

This calculator handles DST automatically using the IANA timezone database. Select the date of your conversion — not just the time — and the correct offset is applied for that specific day. For example, 14:00 UTC on 2026-01-15 equals 9:00 AM EST (UTC-5), while 14:00 UTC on 2026-07-15 equals 10:00 AM EDT (UTC-4).

UTC to PST works the same way: Pacific Standard Time is UTC-8 in winter, Pacific Daylight Time (PDT) is UTC-7 in summer. Select Los Angeles and the appropriate date for the exact offset.

Related tools for time zone conversions

Time Zone Calculator — converts between any two cities or time zones where neither side needs to be UTC. Use it for questions like “What time is it in Tokyo when it is 3:00 PM in New York?”

Time Difference Calculator — answers “how many hours apart are two time zones?” Use it when you need the gap in hours and minutes, not a specific converted time.

Military Time Converter — converts between 12-hour AM/PM and 24-hour format within a single time zone. Use it when the format of the time is the question, not the zone.