This bitmask specifies the day or days of the week on which a recurring (periodic) time-range entry stops being in effect, choosing from Sunday through Saturday, and the MIB notes the same day can be used in both the start and end day objects. Admins set this together with hm2AgentTimeRangePeriodicStartDay to bound a weekly recurring schedule. For example, an admin scheduling a Monday-through-Friday rule would set the same weekday bits here as in the start day object to close out each day's window correctly.