Sorting Dates in a Pivot Table is not working

I have a Pivot Table with a list of dates. The next column has hours. I am trying to sort by date. I want both instances of June 11 to occur together so that the 2nd instance with -8 hours will appear below the first occurrence with 8.0 hours. The same for June 12, etc. Here is what I am getting.

Hours Date Sum of Entered Hours
June 11, 2012 8.00
June 12, 2012 8.00
June 13, 2012 8.00
June 14, 2012 8.00
June 15, 2012 8.00
June 18, 2012 4.00
June 19, 2012 10.00
June 20, 2012 10.00
June 21, 2012 9.00
June 22, 2012 9.00
June 11, 2012 -8.00
June 12, 2012 -8.00
June 13, 2012 -8.00
June 14, 2012 -8.00
June 15, 2012 -8.00
June 18, 2012 -4.00
June 19, 2012 -10.00
June 20, 2012 -10.00
June 21, 2012 -9.00
June 22, 2012 -9.00

The dates are in date format. Why are similar dates paired together?