Daily timesheets are most prevalent where each person enters the time invested on each project every day. You can use the handy comments section to request more information from your employees too.
Often the methodology is based on the employee type. Senior staff who lead teams and are not performing individual tasks can put in time by month instead of the daily timesheet.
Timesheet submissions by month take the least amount of time, but they also give you the least amount of information on how the time was invested. Daily timesheets give you more details on how the time was invested.
Collecting time metrics from all employees will ensure accurate reporting on both effort invested and productivity analysis.