The data was originally passed in as a query, a query generated from cfpop.
although, the data column is a varchar. Since a query must be passed in, I
attempted to do a query of query on the cfpop recordset and cast the date
column to a DATE or TIMESTAMP. And then pass in the new query into the cfgrid.
FYI, casting to a DATE datatype does not work, though casting to a TIMESTAMP
does. An example below

<cfpop name="popmail" action="GETALL" server="*" username="*" password="*">

<cfquery name="qrymail" dbtype="query">
SELECT CAST([date] AS TIMESTAMP) AS popdate FROM popmail
</cfquery>

<cfdump var="#GetMetaData(qrymail)#">

<cfform format="flash">
<cfgrid name="gridmail" query="qrymail">
<cfgridcolumn name="popdate" mask="MM/DD/YYYY"/>
</cfgrid>
</cfform>