If you have an employee who is getting overtime, and they are not entitled to it;
Go to the Employee Card, Employment, Employment and check the Award that the employee is on.
Then go to Setup, Awards, select the Award, and double click on it to open it up.
Select Normal and then double click on Normal Times as per the image below, check the hours that have been set up in the listing of Monday to Sunday, and amend these times accordingly.
Often, adjusting these hours will eliminate overtime if it has been incorrectly set up.
Note: Always check your individual Awards for the correct span of hours over a day before adjusting.