blue | Western European Time (UTC+0) Western European Summer Time (UTC+1) |
light blue | Western European Time (UTC+0) |
red | Central European Time (UTC+1) Central European Summer Time (UTC+2) |
yellow | Eastern European Time (UTC+2) Eastern European Summer Time (UTC+3) |
orange | Kaliningrad Time (UTC+3) |
green | Moscow Time (UTC+4) |
Coordinated Universal Time (or UTC) is the standard time system of the world. It is the standard by which the world regulates clocks and time. It is, within about 1 second, mean solar time at 0° longitude.
The standard before was Greenwich Mean Time (GMT). UTC and GMT are almost the same. In fact, there is no practical difference which would be noticed by ordinary people.