Page Activity Report
If you want to see who did what at what day, you can use the "Page Activity Report", this is located at this location : http://<server:port>/etc/reports/auditreport.html.
The report offers you a great source of information on how the system is used, and you have a lot of freedom on defining your reports. Via the column-headers you can filter / aggregate and group on the values of the columns.
When you have grouped a column, you have a graphical representation that enables you to drill down to the information you want to inspect.