Soviet Update--Film at 11:45: The Vremya TV news program, a fixture in the Soviet Union for 21 years with its once-a-day newscast at 9 p.m., now will be broadcast three times a day with two anchors, reflecting a more Western approach to TV news. "The format change is because of the increased flow in information," Ivan Ilyoshin, a senior editor of the Vremya (Time) program, said Wednesday. On Monday, Soviet viewers for the first time saw an anchorman and anchorwoman reading the news under soft lights, sitting behind low desks. A third person reported sports. Vremya now will have half-hour TV news programs at 12:30, 6:30 and 9 p.m., plus a news summary at 11:45 p.m.