Employee deserves comp time–but on whose timetable?

Q. I know if employees request comp time off, I can deny it if it's a hardship on the department, and then offer them alternate dates. But can I make employees take comp time when I want them to? Say an employee has 60 hours on the books and I want them to get that time off. Can I pick the dates they must take it, even if they do not want those dates off? – Jackey, Georgia