Include a filter parameter for Overtime hours in GetSumOfTimesheetReportHoursForGivenPeriod() function

I would like the ability to be able to use the GetSumOfTimesheetReportHoursForGivenPeriod() function to work out the sum of overtime hours and non-overtime hours. 

For that, I think I need a parameter option within the function to be able to choose whether I want:

• Non-over time only
• Over time only
• Over time and non-over time combined