Jake, Charlie and others in “City of Great Racks”

Hot girl at twelve o'clock.

Where?

Over there.

That would be nine o'clock.

No, it's twelve. Actually, it's 12:05. Twelve-ish.

You want to straighten him out, or should I?

Go ahead, take a swing.

OK, the reason guys say "Hot girl at", like, "twelve o'clock" or "three o'clock" is to specify a location using the clock face as kind of a map.

What if you have a digital watch?

First of all, you're not gonna meet any women if you're wearing a digital watch.