On 2009-08-12, The Wanderer wrote:

On Wed, 12 Aug 2009 15:42:09 +0100, PeterC wrote:

The electrician said that the meters are supplied as GMT only and warned me
about being on the higher rate at 0700 in the winter.

Seems fair enough to me. Also suggests you're getting E7 up till 08.00
now....

It's a bit like BT or some [other] ISP changing the times.

No it isn't. You're getting E7 for a seven hour period within the wider
time envelope as published by your electricity supplier.

But you need to know in advance what period you will actually get so
you can set the appliance timers properly.