Je pense que j'ai trouvé.
Si quelqu'un trouve plus court ou plus facile ....
Declare @strYear as varchar(4)
Declare @strMonth as varchar(2)
Declare @strDay as varchar(2)
Declare @strDate as varchar(10)
Declare @strStartas varchar(8)
Declare @strEndas varchar(8)
Declare @dStart as datetime
Declare @dEnd as datetime
Declare @iDiff as int
Set @dStart = '20060511'
Set @dEnd = '20060530'
Set @strYear = substring(@strStart,1,4)
Set @strMonth = substring(@strStart,5,2)
Set @strDay = substring(@strStart,7,2)
Set @strDate = @strYear + '-' + @strMonth + '-' + @strDay
Set @dStart = CAST(@strDate AS datetime)
Set @strYear = substring(@strEnd,1,4)
Set @strMonth = substring(@strEnd,5,2)
Set @strDay = substring(@strEnd,7,2)
Set @strDate = @strYear + '-' + @strMonth + '-' + @strDay
Set @dEnd = CAST(@strDate AS datetime)
Set @iDiff = DATEDIFF(day, @dStart, @dEnd) + 1
Jakata