gridSpy: 'daily' data is actually 2.5 days

usually starting from 11:00 the previous day so for example:

hum-csafe/Research Projects/GREEN Grid/_RAW DATA/GridSpyData/rf_06/18Nov2017-19Nov2017at1.csv

starts at 17/11/2017 11:00 and ends at 19/11/2017 10:59

So there will be duplicated data across the files