In postmeditation practice, after you meditate, being right on the dot means to be present every waking moment. Whatever you are doing, you should be in contact with reality as much as you can. You could be right on the dot while taking a shower. You could communicate with the sights, sounds, feelings, and temperatures around you.
From “Leading a Spotless Life” in The Path of Individual Liberation, Volume One of The Profound Treasury of the Ocean of Dharma, by Chögyam Trungpa, page 225