I am with William. We have a definite sick policy, with 6 personal days. The personal days can be banked, or used for what ever the employee feels the need to use them for. If they are sick, it is a sick day, if they are on vacation, it is a vacation day, if they want to use it while they are on jury duty, that is their choice. If it is just a day too beautiful to work, guess what...The only thing I will say no to is if it is a beautiful day, and they are the second one to call in. If it is vacation, it needs to be prescheduled. Sick can't be helped, but I will ask for a Doctors note if there is a trend.
The advantage is, they can bank them, and if they want to use 12 the next year, and they have them saved, they can. Screwy, but it works.