Menachem Mendel Schneerson — American Leader born on April 18, 1902, died on June 12, 1994

Menachem Mendel Schneerson, known to many as the Rebbe, was a Russian Empire-born American Orthodox Jewish rabbi, and the last Lubavitcher Rebbe. He is considered one of the most influential Jewish leaders of the 20th century... (wikipedia)

Not only will this make you treat each moment more preciously, but you will be more patient with yourself and with others, recognizing that there are millions of moments on the path to any worthwhile achievement.
We are always rushing to an appointment or trying to meet a deadline.
Before the day begins, you are not yet engaged in any physical activities. And it is only physically that you are constrained by the limits of time and place; mentally, there are no such boundaries.
This is the key to time management - to see the value of every moment.
You cannot add more minutes to the day, but you can utilize each one to the fullest.