The swiftness of time is infinite, as is still more evident when we look back on the past.
Seneca

Thrift of time will repay you in after-life with a thousandfold of profit beyond your most sanguine dreams.
William E. Gladstone

You may as well borrow a person’s money as his time.
Horace Mann

Those that make the best use of their time have none to spare.
Thomas Fuller

To comprehend a man’s life, it is necessary to know not merely what he does but also what he purposely leaves undone. There is a limit to the work that can be got out of a human body or a human brain, and he is a wise man who wastes no energy on pursuits for which he is not fitted; and he is till wiser who, from among the things that he can do well, chooses and resolutely follows the best.
John Hall Gladstone