Read and modify a BACnet Schedule object's weeklySchedule, exceptionSchedule and effectivePeriod to change occupancy setpoints

Documented steps

1. Confirm the object and its properties. A ScheduleObject (objectType 'schedule') requires presentValue, effectivePeriod (a DateRange with startDate and endDate), scheduleDefault, listOfObjectPropertyReferences and priorityForWriting, plus optional weeklySchedule (ArrayOf DailySchedule, length 7) and exceptionSchedule (ArrayOf SpecialEvent).
2. Read generically with bacpypes3: await app.read_property(address, objid, 'weekly-schedule' | 'exception-schedule' | 'effective-period'). The console equivalent is 'read <address> schedule,<inst> weekly-schedule'.
3. Each DailySchedule is a SequenceOf(TimeValue), a list of (time, value) pairs for that day. weeklySchedule holds exactly seven of them, Monday through Sunday.
4. Read priorityForWriting first. The Schedule writes into its controlled objects' priority arrays at that level, so you need to know which slot it owns before you command the same points from anywhere else.
5. In BAC0 use the higher-level helpers: schedule = await bacnet.read_weeklySchedule(address, instance) returns a dict shaped like {'states': {...}, 'week': {'monday': [('1:00','Occupied'), ('17:00','UnOccupied')], ...}}. Modify it and call bacnet.write_weeklySchedule(address, instance, schedule).
6. For exceptions, write exceptionSchedule with bacpypes3 directly. Each entry is a SpecialEvent(period, listOfTimeValues, eventPriority) where period is a SpecialEventPeriod choice of an inline calendarEntry or a calendarReference ObjectIdentifier pointing at a Calendar object.
7. Write with await app.write_property(address, objid, prop, value, array_index, priority), priority 1-16 when supplied. Console: 'write <address> schedule,<inst> weekly-schedule[<idx>] <value> <priority>'.
8. Re-read presentValue plus eventState and reliability on the Schedule object to confirm the change was accepted and the object is not reporting a fault.
9. Access requirement: none at the protocol level; schedule writes are unauthenticated BACnet writes.
10. Official documentation verified 2026-07-30: https://bac0.readthedocs.io/en/latest/schedules.html | https://raw.githubusercontent.com/JoelBender/BACpypes3/main/bacpypes3/object.py | https://bacpypes3.readthedocs.io/en/latest/gettingstarted/running.html