Date range for Contextual Filter, "Provide default value", Type: Fixed value?

If it is NOT currently possible through the UI then a realisation of this feature can't be too far away, as I noticed when I got Views to output the query executes that it generates something like this for this case of a Fixed value of "201203". This is regardless of whether the "Start/End date range" radio box is selected:

...
WHERE (( (DATE_FORMAT(field_data_field_riks_date.field_riks_date_value, '%Y-%m') >= '2012-03' 
AND DATE_FORMAT(field_data_field_riks_date.field_riks_date_value, '%Y-%m') <= '2012-03') ))
...

Ok, so it is possible.
Found by trawling through the source code that the "to" separator is double-hyphen (--).
Example: 2012-03-25--2012-03-31.
Is this Views' best kept secret?

For more more flexible date and other ranges, see this module: http://drupal.org/project/contextual_range_filter