
“In the end, today is forever, yesterday is still today, and tomorrow is already today.”
My Heart's in the Highlands (1939)
Came from an online quiz falsely attributed to Schulz http://www.snopes.com/glurge/schulz.asp. However, in the 13 June 1980 Peanuts strip http://www.gocomics.com/peanuts/1980/06/13, Marcie does say "I promise there'll be a tomorrow, sir. In fact, it's already tomorrow in Australia."
Misattributed
“In the end, today is forever, yesterday is still today, and tomorrow is already today.”
My Heart's in the Highlands (1939)
“Remember, today is the tomorrow you worried about yesterday.”
Source: How to Stop Worrying and Start Living (1948), p. 237. Part 8 : How I Conquered Worry,
“I'm not worried about tomorrow, because God is there already, waiting for me.”
Source: Manuscript Found in Accra
“I'm having too much fun today to worry about tomorrow.”
A Conversation with Ward Cunningham (2003), To Plan or Not To Plan
Context: To worry about tomorrow is to detract from your work today. Time you spend thinking about tomorrow is time you're not spending thinking about what to do today. The place you leave in the code because you think you'll need it tomorrow, is actually a waste of time today — and a liability tomorrow. It does more harm than good.
“Do not worry about tomorrow, for tomorrow will worry about itself..”
Source: Have a Little Faith: a True Story