Once again, usage in the 8 PM hour was down week-to-week as viewers adjust to the switch to daylight saving time. Last night, the drop was bigger than usual, 12.4%. All 8 PM shows were impacted. Fox’s American Idol (5.6/18 in adults 18-49, 19 million viewers) was down the most, 16%, from last Thursday. ABC’s Winter Wipeout (2.0/7) was down 9% from its most recent original on Feb. 24. NBC’s newly renewed Community (1.7/6) was down 6% for a season low, while new comedy Perfect Couples (1.2/4) was down 14% from Feb. 24 for a series low.

At 9 PM, Fox’s Bones (3.4/10, 11.9 million) bucked the down trend, up 6% in 18-49 and 13% in viewers from last week. ABC tried out 10 PM medical drama Private Practice in the tentpole 9 PM position occupied by the series that spawned it, Grey’s Anatomy. The result was not pretty: Private Practice drew a 1.9/6, down 17% from its most recent original for a series low. Following an Office rerun, NBC’s Parks and Recreation (1.8/5) was down 25% from its last original, which followed a new Office, to tie its series low. NBC had the only original offerings in the 10 PM hour: 30 Rock (1.7/5), down 26% for a series low, and Outsourced (1.4/4), flat and tied as a series low.

CBS had NCAA men’s basketball in primetime. There is no reliable ratings data yet, but the game is expected to be down with NCAA coverage expanding from one network, CBS, last year, to four this year. However, the combined rating for college basketball yesterday on CBS, TNT, TBS and truTV hit a 20-year high.