Finding the end date for the active Sprint

I am defining the following calculated member for finding the end date for current active sprint across all the boards in my project :

NOT [Sprint].CurrentMember.getBoolean(‘Closed’)

– Filtering the Active sprint on the board
[Sprint].CurrentHierarchyMember.get(‘End date’)

I am selecting the formatting as mm dd yyyy . However i’m not getting any date in the result rather i’m getting the text “mm dd yyyy”