[ApxaHGe1]

Ни разу не занимался разбором компонентов. В dbgrideh.pas есть такое

Код:

function FormatFieldDisplayValue(Field: TField; DisplayFormat: String): String;
begin
  if DisplayFormat = '' then
    Result := Field.DisplayText
  else if Field.IsNull then
    Result := ''
  else if Field is TNumericField then
    Result := FormatFloat(DisplayFormat, Field.AsFloat)
  else if Field is TDateTimeField then
    DateTimeToString(Result, DisplayFormat, Field.AsDateTime)
{$IFDEF EH_LIB_6}
  else if Field is TSQLTImeStampField then
    DateTimeToString(Result, DisplayFormat, Field.AsDateTime)
{$ENDIF}
  else if (Field is TAggregateField) and (TAggregateField(Field).ResultType in [ftFloat, ftCurrency]) then
     Result := FormatFloat(DisplayFormat, Field.Value)
  else if (Field is TAggregateField) and (TAggregateField(Field).ResultType in [ftDate, ftTime, ftDatetime]) then
    DateTimeToString(Result, DisplayFormat, Field.Value)
  else
    Result := '';
end;

Если тут поменять datetime на date. Это не поможет?