Nombre de jours entre 2 dates

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