CBS News[3] and MPR (AP) report from the ceremony on 'Sunday, Feb. 12, 2012' in Los Angeles; Wikipedia[2] places it at Staples Center. No start time is stated, so all-day.
At the 54th Grammys at Staples Center, Adele won all six of her nominations, including Record, Song and Album of the Year, tying Beyoncé's one-night record for a woman. Whitney Houston had died the day before; host LL Cool J opened the show with a prayer and Jennifer Hudson sang 'I Will Always Love You'.