I believe the issue here is that you would like the labels to be at the bottom of the bars rather than the top? Currently, the way to do this is by way of a workaround (this would be a good one to add to the Ideas section--if it's not already there). Make a duplicate of the date field, and place both the original and copy of the date field on the view. Then, right click on the first instance in the columns shelf and uncheck 'Show Header.'
Hope this helps!