I've taken advantage of AMC Movie Theaters' weekend and holiday morning deals for some time: movies starting before noon on Friday-Sunday and on holidays have been $5 or $6 regardless of how new the movie is (with up-charges for extras like 3D or IMAX). Now, AMC has extended that deal to cover Monday through Thursday and, even better, for all day on those four weekdays.
The AMC Weekday Escape works similarly to the weekend/holiday before noon deal and does have an "Upcharge for IMAX, IMAX 3D, Digital 3D, ETX, ETX 3D, premium locations, and special presentations." It is also important to note that movies with a weekday opening day (like this week's Twilight Eclipse) are not part of this deal the week they come out.
See the AMC Weekday Escape page for more details.