In the policy of attendance requirements what is meant by "Scheduled time off" and "unscheduled time off"?

A perspective that is used often in Branches Management more than companies (since companies have a strict time off policies and procedures) the scheduled time off is the balance of shifts between employees to cover the gap of the absent individual in order to maintain the work flow with no further delay or hassles

Scheduled Time Off

Definition: An absence for which the staff member has notified the supervisor in advance and has obtained approval to be away from or late to work.

• Scheduled time off is preplanned with the supervisor in accordance with department or unit guidelines by negotiating for the least impact of the time off on the rest of the entity’s workforce.

This form of time off includes absences such as vacations, holidays, personal days, medical or dental appointments, bereavement leaves, and military leaves and is understood as any absence from work that is authorized by the supervisor.

Unscheduled Time Off

Definition: Time away from work that is not approved in advance by a supervisor.

• In the event that the staff member is absent for consecutive days of scheduled work due to sickness, injury or approved personal reasons, only the first day will be counted as an occurrence of unscheduled time off, if he or she arranged for the additional time off with the supervisor.
• This form of absence is also understood as any unscheduled time off, no show, failure to report for or remain at work as scheduled without advance supervisory approval.
• A staff member who reports to work after more than50 percent of the shift has elapsed will be considered as having taken unscheduled time off.
• An early departure from work before completing50 percent of the shift is also considered as an unscheduled time off.

Unscheduled time off may be for a full shift and/or day, multiple shifts and/or days, or a portion of a shift and/or day.

Thanks to a colleague  HASSAN on this answer

Agree with Hasan....

agree with mr. hasan and mr.VENKITARAMAN KRISHNA MOORTHY VRINDAVAN