WTD = Ref period = continuos average of 48 hrs in a 52 week ref period or 1 year or in a 2 x 26 week period or 3 x 17 week period? If this is so where is the 52nd week in the 3 x 17 week reference period? Or have I had a senior moment?
There’s no such thing as a 52 week reference period. Its either 17 or 26 week. Doesn’t have to add up to 52 weeks.
By 52 weeks I meant continuous. Aren’t 2 x 26’s 52? If you are correct (and I have no reason to doubt you) then the 17’s just keep rolling yes? And a fixed week is 7 days of which if I remember correctly there are 52 in a year of which each is an average of hours over a given time. 
have a read