While non-exempt employees must be paid for all time worked, the law allows employers to round an employee's start and stop times. As with most issues under the FLSA, though, what seems simple often is not.
First, of course, before engaging in any rounding, you must have a clearly stated policy that informs employees of exactly how the start and stop times are rounded. Second, once a rounding policy is in place, you must be sure that it is applied to each individual employee in a way that does not disproportionately favor the employer.
Many employers assume that if they consistently follow a well-thought-out rounding policy, the minor adjustments of minutes will work to the employee's benefit as many times as they work to the employer's benefit. However, consider an employee who regularly clocks in four minutes early and clocks out seven minutes late. If rounding to the nearest fifteen minutes causes that employee to lose eleven minutes of time every day, or fifty-five minutes a workweek, the Department of Labor will find a problem.
Even if you have an automated system that handles the rounding function, you should periodically audit time records to ensure that the benefits of rounding flow both ways and that, over time, each employee is fully compensated for all time worked.