Good to see you have the main problem sorted, good luck on the billing side.

The meter clock is set to GMT and dosent change when the clocks go back and forwards. The read on the display defaults to whichever rate is being recorded at the time, i.e. when it's 00:30 meter time the reading will show the low rate (R2) and will switch on the 5th terminal to allow power to the storage heating (accompanied by a clunk in the meter).