The term “mean” indicates the average time the clocks need to pass through the solar day. The name derives from the place where the solar time was standardised for everyone: it was established at The Royal Observatory Greenwich. The abbreviation of GMT stands for Greenwich Mean Time. Nevertheless, both of these time standards are widely used in the world for a similar purpose of time coordination. Although UTC and GMT indicate the same time, UTC is based on the more precise mechanism of time measurement. In particular, the concept of Coordinated Universal Time (UTC) was designed to provide a more accurate timekeeping system. The advancement of telecommunication technologies influenced the creation of an even more precise system of time identification. The primary difference remains to be the fact that GMT is the denomination of a timezone, while UTC is the title of the time standard. Therefore, the difference in time for other countries is indicated either by adding or subtracting hours from GMT time.

The implementation of Greenwich Mean Time (GMT) was the first step to determine the time zone of other countries in regard to GMT+0. Especially, it was vital to have a standardised time zone for communication and military coordinations. With the globalisation and evolution of international relationships, the need for universal time identification has occurred.

Where is gmt time zone