Mark date as a holiday if it is within the valid range.
Mark the specified date as a holiday (i.e., a non-business day) in this calendar if date is within the valid range. Return 0 if date is in range, and a non-zero value otherwise. This method has no effect if date is already marked as a holiday or is not in the valid range. See {Iterator Invalidation} for information regarding which iterators are affected by the use of this method.
0 if date is in range, and a non-zero value otherwise
| Name | Description |
|---|---|
| date | date to mark as a holiday if in range |