select c.Name as [Report Name],   
        e.InstanceName,   
        e.UserName,   
        e.Status,   
        e.Format,   
        e.Parameters,    
        e.Timestart,   
        e.TimeEnd,   
        datediff(mi,e.Timestart,e.TimeEnd) ExecutionTime,   
        e.TimeDataRetrieval,   
        e.TimeProcessing,   
        e.TimeRendering   
from ReportServer..Executionlog e   
inner join ReportServer..Catalog c on (e.ReportID=c.ItemID)   
where convert(varchar,e.TimeStart,112) between 20100101 and 20100123   
order by e.TimeStart desc