If one of my days on or off happens to be a public holiday, I don't get another day off in lieu
Don't know about you but in my time the general populace on an hourly rate of pay got four weeks leave a year plus public holidays, as a pilot we received six weeks leave a year with attendant salary, the two extra weeks leave being recognition of lost public holidays.
Does seniority still enhance your ability to get what you bid for? If so the folk further down the list whose bid goes in the bin might be a darn sight happier if the important days days such as Xmas were spread equitably right across the work force, in this computer age its not beyond the ingenuity of man/woman to devise a program/software.