Greenwich Mean Time - Wikipedia, the free encyclopedia

Greenwich Mean Time (GMT) is a term originally referring to mean solar time at the Royal Observatory in Greenwich, London. It is now sometimes 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 1928. Observations at the Greenwich observatory ended in 1954.

In the UK, GMT is the official time only during winter; during summer British Summer Time is used. GMT is substantially equivalent to Western European Time.^{[citation needed]}

In other words, London is on GMT (or UTC, substantially similar) in winter, on GMT+1 in summer. Paris-Berlin are on GMT+1 in winter (ie now), and GMT+2 in summer.

DoDo and I did some fascinating (for PNers) research into the history of this, in some long-forgotten corner of this blog that I haven't got time to dig out now.

But be assured London is on GMT right now.