Source: Wikipedia
Sleeping while on duty or sleeping on the job refers to falling asleep while on the time clock or equivalent, or else while responsible for performing some active or passive job duty.
While in some jobs, this is a minor transgression or not even worthy of sanctioning, in other workplaces, this is considered gross misconduct and may be grounds for disciplinary action, including possible termination of employment.[1][2]In other types of work, such as firefighting or live-in caregiving, sleeping at least part of the shift may be a part of the paid work time.