Add the CBS chief to the gaggle of broadcast network execs who say that their soft early-season ratings mostly reflect changes in viewing habits — not dissatisfaction with their shows. “DVR usage has been growing, and streaming is pretty new, as is VOD,” Les Moonves told analysts in a call to discuss CBS Corp’s Q3 earnings. CBS shares are down about 10% since the fall season began, in part because investors are concerned about the ratings. (CBS is -17.6% in primetime among 18- to 49-year-olds for the first six weeks.) Things should improve, Moonves says, as Nielsen begins to count the growing number of viewers who watch shows on digital gadgets including smartphones and tablets. And he hopes to fold in many DVR users who record shows and watch them several days later. While the current system counts people who watch ads up to three days after a program airs, “we’re pushing to get it seven days, and we think it will happen in a short time.” With all of the changes, “people have to stop looking at overnight ratings. It’s a different ballgame.” Yet he remains characteristically upbeat that CBS will improve soon. At the beginning of the season many viewers like to sample new shows on other networks, but then return to their familiar favorites. “This past week we had our highest rated week ever,” Moonves says. Advertisers “realize by the end of the year we’re going to be fine” — and CBS won’t have to offer them make-good ads to compensate for ratings shortfalls.