Del Cooper tests shoppers on the pounds shilling and pence of old on this, the filth anniversary of decimalisation and sees just who is capable of giving him the right change. “How much is that in old money?” is a popular phrase coming from Decimalisation Day or D-Day as it is known. A considerable public information campaign prepared the country for changeover on 15 February 1971 with the date deliberately chosen due to it being a low-trading month for banks and shops.