mdx mtd error please help

 I am getting the following error when trying to calculate the MTD function

By default, a month level was expected. No such level was found in the cube.
FORMATTED_VALUE #Error Query (7, 1) By default, a month level was expected. No such level was found in the cube.

I am trying to get the total of the month of april for the year 1995. Here is the code.

MEMBER [Measures]. [hh] as 
mtd([Dim_DateTime].[Calender].[MonthofYear].&[1995]&[4])
				Select
						{[Measures].[Value Actual],[Measures]. [hh]} on columns
from cube

Thanks for your help

-Sarah