For me, if there is an awareness of thinking at all, (about past, present, or future) then I am not truly being present? The great tennis player, Arthur Ash coined the phrase "being in the zone". It refers to the mental state of a person who is totally absorbed in what they are doing and just allowing the knowledge and training of their whole being (of which the mind is only a small part) to function at its highest level. My own experiences of this have occured while playing an intense tennis match, skiing in challenging conditions, piloting an aircraft in crucial situations, and responding to an emergency, to name a few.
I do agree that the thought of either the past or the future can only occur in the present moment. And these suggestions for the skillful use of these thoughts are quite insightful and helpful. Thanks for sharing this perspective.