When I worked in Finance our internal Date extension did actually have Workdays that took into account Stock Market and Bank Holidays.
Me too, it was just a constant filled with bank holidays for the next 6 years
I tried to write this function in Power Query (Excel hell). Gave up after an hour or so.
…now imagine a list of instruments, some of which have durations specified in days/weeks/months (problems already with the latter) and some in workdays, and the user just told your app to display it sorted by duration.