(D) interruptions to perform duties are considered time worked.
When an employee's shift is less than 24 hours, periods when s/he is permitted to sleep are compensable work time, as long as s/he is on duty and must work when required. Only actual sleep time may be excluded, up to a maximum of 8 hours per workday. When work-related interruptions prevent 5 hours of sleep, the employee shall be compensated for the entire workday.