Can we require salaried staff to make up lost time?

Q. We’re a small company (fewer than 20 employees) and don’t keep time sheets. Our entire staff is salaried. We expect employees to make up personal time and sick time (neither of which affects their vacation time or holiday time). Are we wrong to expect that if a salaried employee takes two hours for a doctor’s appointment, he or she should make up that time later? —M.V., Florida