A few months back, my old mechanical meter was replaced with one of these
small white Landis & Gyr jobs that has an LCD display, and a small blue
button to cycle through the available displays of recorded units, totals,
time etc. I check it most days, and was surprised to find that this morning,
at 9am, it was still reading Economy 7 units - or whatever they call them
these days. A few minutes later, the reading had increased by one,
confirming that it was indeed still recording night units. I scrolled
through the readings, and was intrigued to find that the clock was 4 hours
slow, so the meter did indeed 'think' that it was still in the Economy 7
period.

So, does anyone know how the clock is set on these ? I was present, chatting
to the fitter the whole time he was doing the job, and I don't recall him
doing anything to the meter, other than removing it from the box, screwing
it to the board, and wiring it in.

I'm thinking that maybe time synchronisation signals are superimposed on the
grid, and that these meters can read them, or maybe that they have a DSF
type receiver in them for getting the time - in fact now that I think about
it, I have a dim recollection of reading that somewhere. But in either case,
I would have thought that the update was every few seconds, or minutes at
worst, so how did my clock get 4 hours behind in the first place, and why
has it not 'caught up' ? It was correct yesterday, so it's something that's
happened 'suddenly'.

At 11am, it changed over, confirming that this is all down to the clock
having the wrong time. I wonder who, in the event of this carrying on for
any length of time, is responsible for the fact that I would be getting
'cheap' (er!) electricity for 4 hours longer than I should be ... ? :-)

Arfa