This cube is the result of my first attempt. The design has a lot of typographic cues and the timeline is an obvious indicator of where the viewer should "start" and "end" the cube at. For a while, I felt that that was the appropriate solution. Soon, the generic timeline concept lost its appeal.

Final Design: One can argue that the big, sans-serif fonts are again a generic concept. During the development of this second design, I was aiming to keep a lot more breathing space. I wanted to simplify the visual cues to a basic amount. The colors were of biggest use in differentiating the present (gray) from the future (orange) sides.
Using incomplete sentences as a cue to switch sides, the concentric circles, and a few dashed lines were visual cues I felt I utilized the best.