My iPods Clock is not running?

Unless you really, really need to use the iPod as a timepiece I would leave it disabled.
It has been blamed before now for speeding up the rate of battery drain when the iPod is idle. It was also very unreliable when it was running on my iPod - so I just left it turned off after my last software update.

But if you feel you must have it active go into Settings>Date & Time>Set Date & Time. The clock is also set when you sync with iTunes if you use a Mac.