The US will move its clocks back on Sunday at 2am ending the annual ritual of daylight savings time for 2008. Since 2007, the US has observed daylight savings time from the second Sunday in March to the first Sunday in November. Unfortunately for the TV industry, that added two weeks of later sunsets during the meat of the broadcast TV season, since from 1987-2006 the start and end dates were the first Sunday in April and the last Sunday in October.
Does the end of daylight savings time increase TV viewing early in the evening? Based on the long term charts of broadcast evening news (which airs from 6-6:30 Eastern) viewership the answer is yes. Note the ramp up in early November and the drop off in late March.
My guess is that it benefits the first hour of broadcast prime time as well (8-9 Eastern). I'll see if I can figure out how identify that effect in a way that's valid and not crazily time consuming and post again on what I find out.
Update: While this may boost all 8pm shows, what shows, that might need a little help, could get boosted in the coming weeks? Terminator: Sarah Connor Chronicles, The New Adventures of Old Christine, Pushing Daisies and Ugly Betty stand out to me.