Summary Types for Search Results
The Results subtab has several summary tools you can use to organize and show your search results. The Group summary type is the most widely used, as it rolls up results. For any other summary type to work, you need to set a Group to roll up the summary results page. You can use Results summary types in advanced and saved searches. In saved searches, you can also filter and to highlight based on summary values.
Note:
Previously, search results were grouped by time stamp, so it wasn't 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: