“Time isn’t precious at all, because it is an illusion. What you perceive as precious is not time but the one point that is out of time: the Now. That is precious indeed. The more you are focused on time—past and future—the more you miss the Now, the most precious thing there is.”
― Eckhart Tolle, The Power of Now: A Guide to Spiritual Enlightenment

The present is all that you have. You do not know how or what the circumstances would be like in the future. You can’t change what has been done in the past. . Eckhart Tolle, in his book the Power of Now suggested that time is an illusion. There is no past or future. There is only the “Now”. 

Accept, plan, then act.