The process of calculating Overtime is made up of many small error prone calculations. First, the hours for each time card session (when the employee punches in and out) is needs to be calculated by subtracting the time in from the time out. Then all of the time worked sessions need to be tallied. Done right this means adding the Seconds, converting them to Minutes and carrying the excess. Then adding the minutes and converting that to hours and carrying the excess to the hours column, and finally adding the hours.
FLSA (Fair Labor Standard Act) Overtime is based on a work week which usually goes from Sunday to Saturday, but any day of the week and be selected as the first day of the work week. The total hours must be calculated for each work week separately to see any any overtime was incurred in that week.
Another complication arises if you use a monthly or semimonthly pay period. In this case the work week will often be divided between two pay periods, and time from the previous pay period needs to be considered in the overtime calculations of the first work week in the current pay period.
Usually all these calculations are made under pressure of a deadline because you're trying to get payroll out.
The solution to all this error prone drudge work is easy. Just let ShopClock calculate overtime for you. Take the ShopClock4 Tour to see how easy it can be.