I think this has been discussed on various lists before, and it was agreed that it was not from Sanskrit.

Valerie J Roebuck


On 14 May 2012, at 14:10, Anna A. Slaczka wrote:

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