if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[Fn_FinMonth]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[Fn_FinMonth]
go
Create Function dbo.Fn_FinMonth(@MonthCode varchar(2))  
Returns Varchar(2)  
As 
/*------------------------------------------------------------------------------------------------------------------------------------------
** SQLVersion : SQL 2000
** Function	: Fn_FinMonth
** Author 	: Kartik M
** DateTime	: 29 January 2011 22:30
** Version	: 1.2
** Purpose	: To get the financial month from the respective calander month
** ToCheck	:
** Changes	: KM - 06 Feburary 2011 - Change the return type form Numeric to Varchar and add Leading Zeros to avoid problem while sorting
------------------------------------------------------------------------------------------------------------------------------------------*/ 
/*
-- Start of Debugging Stuff
	Declare @MonthCode varchar(2)
	Set @MonthCode = '02' -- Pass the Month Number as Input
-- End of Debugging Stuff
*/
Begin  
	Declare @FinMonthC Varchar(2)  
	Declare @IMonthCode int  
  
	Set @IMonthCode = cast(@MonthCode as int)  
	if @ImonthCode between 4 and 12  
		Begin  
			Set @FinMonthC = @IMonthCode-3
			Set @FinMonthC = Replicate('0', 2-len(@FinMonthC))+@FinMonthC
		End  
		
	Else if @ImonthCode between 1 and 3  
		Begin  
		  	Set @FinMonthC = @IMonthCode+9
			Set @FinMonthC = Replicate('0', 2-len(@FinMonthC))+@FinMonthC
		End  
   
Return @FinMonthC
End  
--Select dbo.Fn_FinMonth ('05')  
go

DECLARE @Varmonth CHAR(2)
SELECT @Varmonth = 04

select @Varmonth =datediff(mm,'1899/04/01',DATEADD(mm,CAST(@Varmonth AS INT) ,0))%12 +CASE WHEN CAST(@Varmonth AS INT) = 3 THEN 12 ELSE 0 END
		
select @Varmonth = REPLICATE('0',2-LEN(@Varmonth))+@Varmonth

select @Varmonth