Oh - i didn't think of the time component. *facepalm. Thanks.

Hmm.. so I created a list with two fields: date, var

inserted 3 rows:

2011-05-01,gg
2011-05-01,hh
2011-05-02,gg

So we probably just need to make sure when displaying this data to create a query that casts it first. Otherwise the user will be coming in trying to filter and not getting any results