After 10 years of planning and 20 months of construction, the new Roeliff Jansen Community Library serving Hillsdale, Copake, and Ancram will open to the public with a celebratory weekend. The ribbon cutting ceremony will be held at 11 a.m. Programs for children and families will follow at 1pm (featuring performances by local artists, John Farrell and Steve Charney) and the Grand Opening Bash will be held at 6 p.m. (featuring performances by The Karl Easton Jazz Group, Soprano Joan Weitzner, The Taconic Hills Jazz Ensemble, and The Taconic Hills Drama Club). The celebration will continue into Sunday with a 2 p.m. talk and book signing by acclaimed biographer, David Nasaw.