Time range inclusive and exclusive

I am new to MDX and want to write an MDX where i want to get a time column with range that start period is inclusive and end period is exclusive.

What I have right now in my MDX is something like this and it returns me both the 8o clock readings and 8:15 also. I only want datetimes that are for 8o click and less than 8:15. Hece 8:15 readings shouldnt be in teh result set. How can I fix that. Please help..

,NonEmpty([Dim_DateTime].[Date Time Id].&[201212310800]: [Dim_DateTime].[Date Time Id].&[201212310815]

Thanks

-Sarah