Time Zone Map - A Great Resource for Networking Around the World

This Time Zone Map is provided for the benefit of those visitors to our site who network with prospects around the world. It is a great resource for checking time zones and planning travel.

To help folks understand how Time Zones and Time Zone Maps came about and the various terms associated with them, I have included some information from Wikipedia here.


A time zone is a region of the Earth that has adopted the same standard time, usually referred to as the local time. Most adjacent time zones are exactly one hour apart, and by convention compute their local time as an offset from Coordinated Universal Time (UTC).

Standard time zone maps can be defined by geometrically subdividing the Earth's spheroid into 24 lunes (wedge-shaped sections), bordered by meridians each 15° of longitude apart. The local time in neighboring zones would differ by one hour. However, political and geographical practicalities can result in irregularly-shaped zones that follow political boundaries or that change their time seasonally (as with daylight saving time), as well as being subject to occasional redefinition as political conditions change.

Greenwich Mean Time (GMT)

Greenwich Mean Time (GMT) is a term originally referring to mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, although strictly UTC is an atomic time scale which only approximates GMT in the old sense. It is also used to refer to Universal Time (UT), which is the astronomical concept that directly replaced the original GMT. In the UK, GMT is the official time only during winter; during summer it's British Summer Time.

Coordinated Universal Time (UTC)

Coordinated Universal Time is International Atomic Time (TAI) with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation. Leap seconds are used to allow UTC to closely track UT1, which is mean solar time at the Royal Observatory, Greenwich.

The difference between UTC and UT1 cannot exceed 0.9 seconds, so if high precision is not required the general term Universal Time (UT) (without a suffix) may be used.

In casual use, Greenwich Mean Time (GMT) is the same as UTC and UT1. Owing to the ambiguity of whether UTC or UT1 is meant, and because timekeeping laws usually refer to UTC, GMT is avoided in careful writing.

Time zones and the associated time zone maps around the world are expressed as positive or negative offsets from UTC. Local time is UTC plus the time zone offset for that location, plus an offset (typically +1) for daylight saving time, if in effect. UTC replaced Greenwich Mean Time on 1 January 1972 as the basis for the main reference time scale or civil time in various regions.


The UTC time zone is sometimes denoted by the letter Z – a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time. This is especially true in aviation, where Zulu is the universal standard. This ensures all pilots regardless of location are using the same 24-hour clock, thus avoiding confusion when flying between time zones.

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