I have a file on this, which would be hard to find at the moment.  The earliest citation I have found antedates Osler's.  It occurs as something one may order in a catalog of the Roycroft Press, which came to me with other family papers, one of my grandfathers having been a fan of the Press's founder, popular sage and devotee of better printing Elbert Hubbard.  I mean eventually to see if it appears earlier or with another attribution in the Roycroft Collection in the Rare Book room of the Library of Congress, or in the archives in the Elbert Hubbard Roycroft Museum in East Aurora, NY.

Allen Thrasher

From: Anna A. Slaczka <annamisia@YAHOO.COM>
To: INDOLOGY@liverpool.ac.uk
Sent: Monday, May 14, 2012 9:10 AM
Subject: [INDOLOGY] Sanskrit proverb?

Dear Friends and Colleagues,
 
A student asked me about a source for this 'Sanskrit proverb' or rather a poem (please see below). I must admit that I never heared it, and it doesn't ring a bell at all.
But perhaps someone has an idea?
 
Best,
 
Anna Slaczka
Amsterdam
Look to this day
For it is life
The very life of life.
In its brief course lie all
The realities and verities of existence
The bliss of growth
The splendor of action
The glory of power
 
For yesterday is but a dream
And tomorrow is only a vision.
But today, well lived
Makes every yesterday a dream of happiness
And every tomorrow a vision of hope.
 
Look well, therefore, to this day.
 
Sanskrit Proverb