The Earth orbits the sun and the moon orbits the Earth. All are dependent on each other for this to continue. The Earth, along with her brothers and sisters, give the sun enough worship to convince it to shine; the moon holds the Earth in balance and keeps her rotation stable. It's quite a beautiful ballet.
The moon, though, is drifting slowly away. Each revolution pulls it a little further, and Earth's days get imperceptibly longer.
One day the moon will be so far away we'll begin to spin chaotically, our understanding of up and down demolished. The sun will rise in the North and set where it damn well feels like it. The days will begin and end in a dizzying, unpredictable spin.
And time will mean nothing. There will be no date to stamp on the end of the world.