The Salaf and the way they valued their time

Al-Hassan Al-Basri May Allah's Mercy be upon him said: “Oh son of Aadam, you are but a few days, whenever a day is gone, part of you is gone too.” 

Al-Qasim Ibn Asakir May Allah's Mercy be upon him was informed that Sulaim Ibn Ayyub May Allah's Mercy be upon him used to give importance to his time. He never wasted any time without doing a useful act. He either wrote books, gave lectures or read. 

Aboo Al-Wafa’ Ali Ibn Aqeel May Allah's Mercy be upon him said: ” I am not allowed to waste an hour of my life. Even when I am not giving lectures or reading, my mind will still be occupied with some issues while I am lying down; and I will not get up until I find something useful to write. And I still find myself striving for knowledge in my eighties more so than when I was in my twenties.”

Al-Hasan Al-Basri May Allah's Mercy be upon him advised his companions saying: “Do not be occupied with ephemeral worldly pleasure and forget the hereafter, your life is short, so hurry up and do not postpone today’s work till tomorrow, because you do not know when you will die and meet Allaah.” 

Al-Hasan Al-Basri May Allah's Mercy be upon him said: “I met some people who were more stingy with their time than their money”

Taken from "wisdom of the wise"