I've previously posted with regard to my hot water and heating both being wired up to the off peak meter even though the storage heaters were replaced by thermal radiators before i moved in.  

What I'm trying to find out is what hours the cheap rate actually is.  If i knew this then i could time my heaters to be on during these times rather than on the expensive rate. I just keep getting told it can be between 5-12 hours which is very vague.

I know it changes depending on weather etc but surely there is a way of finding what those hours are.

The sooner they phase out thtc and change my meter the cheaper it will be for me.

Any help greatly appreciated