Yesterday, Today and Tomorrow

Yesterday was once today.
Today was once tomorrow.
For when today has gone away,
It lives again as yesterday...

Yesterday is in the past.
Tomorrow's yet to come.
We know today can never last.
The present passes very fast.

So, if today you have fall,
Tomorrow you will say,
"Oh, yesterday I had a fall.
Today it doesn't hurt at all!"

But if your birthday is today,
Then yesterday you said,
"Tomorrow is so far away.
How can I wait for one more day?"

The first to come was yesterday.
Today came right behind.
And then will come tomorrow's day.
I don't know why - it's just that way.

-The Young Children's Encyclopedia Britannica (1988), Vol. 15, (P. 52-53)-

This is all about time. When the time passes, tomorrow becomes today, today becomes yesterday. It is future, present and past...