American supervisors expect their employees to arrive on time. An employee who is habitually late to work impacts his/her co-workers because they often have to cover for the missing person.
Imagine your co-worker is late for work at least once a week. What would you do? Would you take your co-worker aside and talk to her? Would you tell your supervisor?
Imagine your co-worker is late for work at least once a week. What would you do? Would you take your co-worker aside and talk to her? Would you tell your supervisor?