If employees arrive early or stay late, can we remove those hours from their timecards?

If the employees are not actually working, you can remove those hours. The applicable federal regulation (29 CFR 785.48, Use of time clocks) states, “employees who voluntarily come in before their regular starting time or remain after their closing time, do not have to be paid for such periods provided, of course, that they do not engage in any work. Their early or late clock punching may be disregarded.”

Although this time can be disregarded, the regulation warns that your records should reflect the hours worked as accurately as possible. Making regular changes to timecards may create the impression that the company is “shorting” the employees or unlawfully trying to avoid paying overtime.