The rink in leonardtown is open weekends but I'm not sure of the hours. It's held in the gym between Leonard Hall and the police barracks. They have skates to rent or you can bring your own.
There is a skating rink in Crofton on Route 301 South. We wanted to take our kids ice skating but we don't feel like venturing to Quiet Waters Park today. Next weekend I suppose!
There is indoor ice skating in waldorf at Capital Clubhouse (they have a website), there is also a roller skating ring in Waldorf, but I'm unsure of the name. It is where Princess Furniture used to be.