Just a note, and I'm not sure about this, but this is what I've heard:
Try not to use any Date/Time fields in views. As NotesDesigner mentioned, it needs to be continually recalculated- and this is not just when it's open. I hear the server ends up having to have to recalculate it all the time. This can tax the server's processing, and give it more work then it really needs.
Please, if someone else knows of this information to be incorrect, please let me know. Thanks.
-MoGryph