To improve the nick of time.

In eternity there is indeed something true and sublime. 

But all these times and places and occasions are now and here. God Himself culminates in the present moment, and will never be more divine in the lapse of all the ages. 

And we are enabled to apprehend at all what is sublime and noble only by the perpetual instilling and drenching of the reality that surrounds us.

H. D. Thoreau,  Walden, Where I lived and what I lived for

See Economy, ("In any weather, at any hour of the day or night, I have been anxious to improve the nick of time, and notch it on my stick too; to stand on the meeting of two eternities, the past and future, which is precisely the present moment; to toe that line.”); April 24, 1859 ("Nothing must be postponed. Take time by the forelock. Now or never! You must live in the present, launch yourself on every wave, find your eternity in each moment. Fools stand on their island opportunities and look toward another land. There is no other land; there is no other life but this, or the like of this.”); May 12, 1857 ("Our past experience is a never-failing capital which can never be alienated, of which each kindred future event reminds us. If you would have the song of the sparrow inspire you a thousand years hence, let your life be in harmony with its strain to-day.”);  June 6, 1857 ("Each season is but an infinitesimal point. It no sooner comes than it is gone. It has no duration. It simply gives a tone and hue to my thought. Each annual phenomenon is a reminiscence and prompting. Our thoughts and sentiments answer to the revolutions of the seasons, as two cog-wheels fit into each other. We are conversant with only one point of contact at a time, from which we receive a prompting and impulse and instantly pass to a new season or point of contact. A year is made up of a certain series and number of sensations and thoughts which have their language in nature. Now I am ice, now I am sorrel. Each experience reduces itself to a mood of the mind. ")