If you're asking why CBS didn't move MAGNUM to 10pm, they also didn't vacate the 10pm timeslot and kept THE EQUALIZER in the same timeslot. DYNASTY's move was primarily triggered by the move of a weaker HOTEL to another night and sudden availability of the 10pm timeslot. They were not going to put a new drama behind a fading DYNASTY. To this day, this remains common practice. REVENGE became a hit in DYNASTY's Wednesday at 10pm timeslot, so it earned a coveted Sunday at 9pm timeslot after the conclusion of DESPERATE HOUSEWIVES. As soon as it became obvious its best days were over (a year and a half later) it got pushed to 10pm, because they couldn't count on it to provide a proper lead-in to new dramas at 10. Beats me. The show suffered the greatest damage while it continued to air in the same timeslot on Wednesdays at 9pm. It does now, but it didn't in the 1980s. Many of the shows ran into May, of course, but the official end of the Nielsen TV season was in April and that's when the year-end seasonal charts came out. Obviously you never got my original point, so naturally you'll dismiss whatever I add on the matter as backtracking. Nevertheless I repeat (as futile as these attempts may be) - the drop from one timeslot to another would have been expected and that wasn't the problem (timeslot expectations vary). The show's inability to hold on to whatever diminished audience it did manage to capture in the new timeslot however was. That inability had to do with the fact the show was past its prime and had almost run its course, not the timeslot itself.