Actually, the "dark side of the moon is referring to the far side, since the moon keeps one face to the Earth.
The Moon rotates just like the Earth does, so it too has a day and a nightime.
The above is the absolute last line on the Pink Floyd album "Dark Side of the Moon".
When the last strains of "Eclipse" are fading and the heartbeat grows in volume, you can hear a faint, man's voice utter the line "There is no dark side of the moon really...as a matter of fact it's all dark."
'Twas just my 2 cents in reply to traumer's #33.
Of all the celestial bodies to be looked at in the night sky, Earth's moon fascinates me like no other. The mathematical coincidences alone boggle the mind. For example, the fact that you stated that the moon rotates once every 30 days so we only see the one side. Why is that? It would seem a near impossibility given the forces that placed it there and act upon it. The fact that it is exactly the right size and distance from Earth to eclipse the disk of the Sun perfectly is another amazing thing.
Without Luna, life as we know it, perhaps even life itself on Earth would not be possible. In my mind, everything about our moon points more than anything else to the existence of a higher power.
But, hey...you're the astronomer. Why am I telling you all this?