Just one thing, though I like this photo alot and think it does an excellent job of depicting "Time", I am a little offended by your crytic "title". You might think that it is harmless, but anything that cryptic isn't usually really harmless. I'm not deducting any on my scoring of your image, just commenting!
I like the interpretation of time that this represents. The light/shadow works very well. I'm not sure if it's the texture of the skull or if the picture is grainy, but I think either way it really adds to the age and impact of the image.