How to make slicer sort dates correctly?

I just discovered the slicer function in Excel 2010 and it seems it could make it a lot easier to quickly show subsets of data in the pivot diagrams.

I've been looking for a similar tool to easily select date ranges for data about usage of our internet site (user contributions, clicked links and more).

However, when I make a slice for the "Date" column, the dates are sorted by date number first and then by month name, instead of in actuall date order:

How I want the slice sorted:
30-May
31-May
01-Jun
02-Jun
03-Jun
...
29-Jun
30-Jun
01-Jul
etc.

How the slice is actually sorted:
01-Aug
01-Jul
01-Jun
01-May
02-Aug
02-Jul
02-Jun
02-May
03-Aug
03-Jul
03-Jun
03-May
04-Aug
04-Jul
ect.

(Also see attached screenshot.)

Example of original data:

Please Login or Register  to view this content.