Description of calendar_x_of_y

     {  CALENDAR_YEAR_NUMBER ( dtexpr [ , nlsparam ] ) ) 
	| ( CALENDAR_QUARTER_OF_YEAR ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_MONTH_OF_YEAR ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_MONTH_OF_QUARTER ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_WEEK_OF_YEAR ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_DAY_OF_YEAR ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_DAY_OF_QUARTER ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_DAY_OF_MONTH ( dtexpr [ , nlsparam ] ) )
	| (CALENDAR_DAY_OF_WEEK ( dtexpr [ , index_by ] [ , nlsparam ] )
    }