It’s an average of the last 10 days, so if it’s between 5pm and 6pm today and you switch everything off at the consumer unit at 5pm, then add the usage up between 5pm and 6pm for the last 10 days (say 1 Kwh per day = 10Kwh) then you’ll save 1 KWh today, this giving you a credit of £2.25 (the per...