Re: time structure without shift

Ian Wilson wrote:
Jürgen Exner wrote:
Now, is GMT the same as UTC or is GMT the local time in Greenwich?

GMT is the same as UTC. For half the year, localtime in Greenwich is
It can be either or but not both.

For half the year it *IS* both. In the winter, local time in Greenwich
is GMT, in the summer the clocks (local time) are switched to BST. GMT
remains the same all year round (and is almost identical to UTC).

The Royal Observatory Greenwich says:
"Throughout the winter months we will be using Coordinated Universal
Time (almost identical to Greenwich Mean Time or GMT).

If even the observatory itself states that UTC is only _ALMOST_(*) identical
to GMT, then why use GMT if you mean UTC?
It is simply good practice to avoid terms that can cause confusion.


(*) For those curiously minded readers: GMT is averaged astronomical time
while UTC is atomic time. Except for very specialized applications (e.g. to
drive a telescope) all computers are using atomic time.