ASHRAE has published a BACnet addendum 135-2008 AC to restrict and clarify what is allowed in the format of calendar entries for single dates and range of date formats in the Calendar object and the exception schedule (the dates you do not want the Schedule to operate, such as holidays).
For a Calendar object Date entry, the entry can be either a specific date or a date pattern:
- a specific date has all fields filled with specific values, and the Day of Week should also have a specific value
- a date pattern has some of the fields with any (wildcard) present
For a Calendar object Date Range entry, the new rules restrict each part (start date and end date) to be one of the following:
- a fully specified date (all fields defined)
- a completely unspecified date (no fields defined - all fields wildcards [any])
Note: No partial wildcard fields for start date or end date are allowed in order to eliminate cases that could not be clearly interpreted and implemented.
Note: The BCPro system currently allows partial wildcard fields for start or end dates leading to unpredictable operation in some cases. You should follow the new BACnet rules and disallow these kinds of entries.