I like this. A real slice of humanity. There's not much variation musically, but then you are writing about boredom, so it works. For the same reason, I think the fade out is the right choice when it comes to ending it - the long day may have ended, but it will just lead to another one.

You wrote:
"can barely see the sunshine
through the cracks in the cage"

but you sang:
"can barely see the sunshine
between the cracks in the cage"

Obviously, the written version makes more sense.