Revised Date format sorts alphabetically not chronologically
 

Hello,
I have a pivot table that is based on an access query. I have a field
called AdmitMonth where the values are 4/1/2008, 5/1/2008 etc. When I do a
pivot graph I have AdmitMonth as my horizonal axis. Since there are 24
months that I want to graph, I would prefer something smaller (i.e. Apr-08,
May-08) but excel won't allow me to change the format of this data field in
my pivot table and chart.

I went back to access and created another field called AdmitMonth2 and used
the following in my query: AdmitMonth2: Format([AdmitMonth],"MMM-YY")

I brought this into my pivot table and then used this as the horizontal axis
in my pivot chart but it now sorts the graph alphabetically by month (Apr-07,
Apr-08).

Is there a way to have this date format (MMM-YY) rather than mm/dd/yyyy but
have it sort by date/time rather than text?

Thanks,