Magnetism and Time? Are they connected?

What is time? And does the magnistism within the earth control it?

As the magnetic core in the earth slowly reverses, can this explain the Zero-point theory?

At the moment, scientists are still working on a Grand Unified Theory that unifies electromagnetism and gravity. We'll have to wait for a theory combining them before we can say much about it. I don't think there's much scientific proof that electromagnetism has any influence on spacetime.

I also think that a magnetic core reversal doesn't explain zero-point theory. In Zero-point theory, quantum fluctations due to uncertainty cause space to have a certain amount of energy. This is everywhere in the universe. It would be kind of silly to assume that the earth's magnetic core is causing this. For more info about zero-point energy, I have found a nice explanation by John Baez here.