City Hall will be open from noon today (Saturday) to 6 p.m. and again on Sunday to give family, friends and the curious a chance to bid final farewell to the late ex-mayor Vincent A. ‘Buddy’ Cianci Jr., whose coffin will be lying in state outside the second-floor mayor’s offices he occupied on and off for 21 years.Those attending the calling hours will enter via the building’s Washington Street entrance.