Who said "Don't watch the clock; do what it does. Keep going."?

This quote is attributed to Spencer Tracy.

Don't watch the clock; do what it does. Keep going. - Spencer Tracy

"Don't watch the clock; do what it does. Keep going."

Spencer Tracy Perseverance

Actor American 1900–1967

"The best way to find yourself is to lose yourself in the service of others."

"There is a nobility in compassion, a beauty in empathy."

"Success is not final, failure is not fatal."

"The only way to do great work is to love what you do."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."