Facing Problem with datediff Subtotal Function

I have a Calculated time Difference Between Dates result are accurate when i see data datewise but in Subtotal Area i Want Sum.

How i can do this in Excel Power Pivot Data Model.

Measure

Time Spend in Hrs = DATEDIFF(MIN(B2B[Check In]),MAX(B2B[Check Out]),MINUTE)/60

result

Result i need Like this.