JEDDAH, 10 May  — The United States Consulate General here is changing the timing for American Citizen Services, according to a press release of the Consulate General yesterday. Effective Saturday, May 12, 2001, the American Citizen Services section will be open from 1 p.m. to 3.30 p.m. Saturday to Wednesday (closed for US holidays). American citizens requiring services outside these hours should call the consular section at 6670080, ext. 4153 or 4164 and make an appointment.