Woodcraft is a national retailer that offers woodworking classes, and people can contact local stores to ask about weekend classes. In Santa Clara, California, The Sawdust Shop offers weekend classes for carpentry beginners and experienced woodworkers who want to learn new skills. Some woodworking schools offer weekend courses, and these classes usually focus on specific furniture carpentry techniques.
Woodworking-News.com has a database of woodworking schools listed by state, and it's possible to find weekend carpentry courses by contacting local schools. However, weekday courses are more common than weekend ones. The Philadelphia Workshop offers weekend classes for people seeking to learn carpentry skills. This nonprofit woodworking studio teaches furniture-making techniques and woodworking skills at all levels, including building whole pieces of furniture. Students learn techniques like operating a tablesaw, chiseling, planecraft and veneering, and it offers a course in which students build their own workbenches.
The Center for Furniture Craftsmanship is another educational organization that offers some weekend carpentry classes. It has full-day classes on Saturdays and Sundays, and its schedule of classes is found at its Community Class page. Students must be 16 years of age or older to take carpentry classes at CFFC, and class tuition is due at the time of registration.