I don't know in general, but at my local theater here in NorCal there was a 9pm and a midnight showing last night.
I don't think there's anything 'wrong' with the late night # for Anchorman 2. I'm personally still higher than the low-ball #s out there for this weekend and still expect it to be the #2 film of December by a comfortable margin, but that late night # also doesn't scream massive break-out to me either (i.e. $200 m+ total). In saying that, obviously extremely early.