The Planning Board on Thursday will continue public hearings on four zoning proposals for the Sept. 23 Town Meeting. One is a request by Oracle America to rezone property at 6, 8, and 10 Van de Graaff Drive from general industrial to high-rise industrial. The company wants to construct a parking garage on the site, part of an existing Oracle campus off South Bedford Street. Another is the proposal by the Gutierrez Co. to rezone 15.3 acres off Route 3 to general industrial. Gutierrez plans to develop an office building on the Wheeler Road site. The other zoning proposals would create new rules regulating outdoor lighting in town, and revise rules relating to Planned Development Districts. All of the hearings opened on July 18.