Summary Types for Search Results
The Results subtab of the search page includes several summary tools you can use to compile and display search results on a summary results page. The Group summary type is the most widely used, as it is used to roll up results. For any other summary type to work, you also need to define a Group, to provide the rollup for the search's summary results page. Results summary types are available for advanced searches and saved searches. Saved searches also let you define filters based on summary values and to highlight summary values.
Previously, search results were grouped by time stamp, so it was not possible to display a single day's results in one group, unless all occurred at the exact same time. To group search results by date, define a Group summary type for a date field on a search page Results subtab.
For details about summary types, see the following: