Forms :: Format Row Source As Long Date

the source table needs to be formatted as short date...my form is pulling data from a query and I would like to change the row source of my combo box on the form to be formatted in long date. row source is as followed

Code:
SELECT [qrydateSUM].[day of event] FROM qrydateSUM ORDER BY [day of event];

I have tried this with no luck

Code:
SELECT [qrydateSUM].format([day of event],"long date") FROM qrydateSUM ORDER BY [day of event];

also changing the format option in combo box doesn't work...im thinking to add a day column to query...but there has to be a way to change row source