BACnetStack_AddCalendarDateEntry

bool BACnetStack_AddCalendarDateEntry(
  const uint32_t deviceInstance,
  const uint32_t calendarObjectInstance,
  const uint16_t year,
  const uint8_t month,
  const uint8_t day,
  const uint8_t weekday);

Appends a Date entry - a specific date or a date pattern - to a stack-held Calendar’s Date_List.

The entry is the date arm of the BACnetCalendarEntry CHOICE (cl. 21). Each field is matched independently and every specified field must match (cl. 12.9.6): for example month 12, day 25 with year 0 and weekday 255 matches December 25 every year.

BACnet reference: ANSI/ASHRAE 135-2024 clause 12.9 (Calendar Object Type).

Parameters

Parameter	Direction	Description
`deviceInstance`	in	The device instance that owns the Calendar object.
`calendarObjectInstance`	in	The stack-held Calendar (BACnetStack_AddCalendarObject()).
`year`	in	The FULL year, 1900..2154 (e.g. 2026, not 126), or 0 = any year.
`month`	in	1..12 (January = 1), 13 = odd months, 14 = even months, 255 = any.
`day`	in	1..31, 32 = last day of the month, 33 = odd days, 34 = even days, 255 = any.
`weekday`	in	1..7 (Monday = 1), 255 = any.

Returns

True on success; false if the device does not exist, the Calendar is not stack-held, a field is out of range, or Calendar support was not compiled. Fields are range-checked, not cross-checked: an impossible combination such as month 2 day 31 is stored and simply never matches. Entries are appended as given - adding the same entry twice stores it twice.

Topic: Schedules, calendars, trend logs and other object configuration. Declared in CASBACnetStackDLL.h.