something happens at the exact set time.

It means something has a lack of subtlety or nuance. Eg: "The comedy tried to make light of the current political climate, but many of the jokes were a little on the nose." There is an entirely different meaning to the phrase "dead on the nose" or "right on the nose" - which essentially means you're on target/have met the requirements of something

Too direct... almost 'rude'...