Utility Value by year, month and date ordered. Uses AFN functions

utilityByYearMonthDate

prefix xsd: <http://www.w3.org/2001/XMLSchema#> 
prefix gol: <http://cofog01.data.scotland.gov.uk/def/golspie/> 
prefix qb:  <http://purl.org/linked-data/cube#> 
prefix buildingCode:  <http://cofog01.data.scotland.gov.uk/id/facility/> 
prefix fn: <http://www.w3.org/2005/xpath-functions#> 
prefix util: <http://cofog01.data.scotland.gov.uk/def/golspie/> 
prefix skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX afn: <http://jena.hpl.hp.com/ARQ/function#>

select ?year ?month ?day (sum(?o) as ?val )

where {  

?slice gol:refBuilding buildingCode:AB0001 ; 
       gol:reportDateTime ?dt ; 
       qb:sliceStructure gol:sliceByDay; 
       qb:observation ?obs .

?obs  gol:utilityConsumption ?o ; 
      gol:refUtility util:electricity . 

filter (xsd:dateTime(?dt) >= '2011-06-11T00:00:00Z'^^xsd:dateTime && 
        xsd:dateTime(?dt) < afn:now())
}
group by (year(?dt) as ?year) (month(?dt) as ?month)  (day(?dt) as ?day) ?obs
order by ?year ?month ?day ?obs

limit 20000