BloombergLP::bdlt::Calendar::unionNonBusinessDays

Description

Merge the specified other calendar into this calendar such that the valid range of this calendar becomes the union of the two calendars' ranges (or the minimal continuous range spanning the two ranges, if the ranges are non-overlapping), and the weekend days and holidays for this calendar become the union of those (non-business) days from the two calendars -- i.e., the valid business days of this calendar become the intersection of those of the two calendars after each range is extended to cover the resulting one. For each holiday in either calendar, the resulting holiday codes in this calendar will be the union of the corresponding original holiday codes. See {Iterator Invalidation} for information regarding which iterators are affected by the use of this method.