You can collect two types of Event Timesheet
Guest timesheets - to record how much time a guest (contact) has spent at an event
Staff timesheets - to record how much time a colleague (in their capacity as Event Worker or Event Manager) has spent at an event
Timesheets are itemised on the Manage Timesheets page
View event timesheet stats (e.g. total time spent within a date range according to different filters)