A floating holiday is a paid day off from work that you can take whenever you like, as opposed to a specific day off like Presidents' Day or Columbus Day.
Some employers offer their employees paid time off as part of their job benefits. Often, specific days are designated as paid holidays — such as Thanksgiving and New Year's Day. A floating holiday allows employees to take a paid day off to observe a holiday of their own choosing. It is usually offered in lieu of a fixed holiday that some employees may not want to observe.