This will give the frequency of results broken down by day, month and year.
You can access this by selecting the 'Date' option in the 'Summary of Results' group in the 'Select a task..' drop down menu on the results screen.
A table will be generated displaying each day for which there is a match to the query with the number of matches next to it. These will be grouped into months with the number of matches in that month alongside and similarly these will be grouped into years.
At the foot of the page there will be a table giving the frequency of each date type in the results.