World Clock Calculator

The calculator first converts your reference time to UTC by subtracting the reference city's UTC offset. It then adds each target city's UTC offset to that UTC time to produce the local time in each location. This two-step process works correctly even for offsets involving half or quarter hours, like India (UTC+5:30) or Nepal (UTC+5:45).

UTC (Coordinated Universal Time) is the world's primary time standard. A UTC offset is the difference, in hours and sometimes minutes, between a city's local time and UTC. For example, New York in Eastern Standard Time is UTC-5, meaning its clocks run 5 hours behind UTC.

When you add or subtract hours across time zone boundaries, the result can fall on the previous or next calendar day. For instance, if it is 11 PM on Monday in New York (UTC-5) and you convert to Tokyo (UTC+9), the equivalent local time in Tokyo is already 1 PM on Tuesday — a full day ahead.

The calculator uses fixed UTC offsets selected from the dropdown. Since DST shifts are seasonal and vary by country, always double-check the current offset for regions that observe DST (such as the US, most of Europe, and Australia). For example, New York switches between UTC-5 (EST) and UTC-4 (EDT) twice a year.

Enter the proposed meeting date and time in your local city as the reference, then add your attendees' cities as Location 1, 2, and 3. The table and bar chart will show you each attendee's local time at a glance, helping you find an hour that falls within normal working hours for all parties.

The current calculator supports one reference city and up to three target locations simultaneously. For larger meetings with more participants, you can run multiple conversions by changing the selected cities and re-calculating.

GMT (Greenwich Mean Time) and UTC are nearly identical for everyday purposes and are often used interchangeably. The technical difference is that UTC is an atomic-clock-based standard maintained by international bodies, while GMT is a time zone historically based on mean solar time at the Greenwich meridian. For time zone calculations, they can be treated as the same.

The furthest offsets from UTC are UTC+14 (Line Islands, Kiribati) on the positive side and UTC-12 (Baker Island, US Minor Outlying Islands) on the negative side — a span of 26 hours between the world's earliest and latest clocks at any given moment.