Sydney J. Harris? Beulah Schacht? Sol Margoles? Evan Esar? Anonymous?
Quote Investigator: Here is a family of closely related statements with dates:
1954 Oct: The time to relax is when you don’t have time for it.
1954 Nov: The time to relax is when you’re too busy to relax.
1960 Nov: The best time to relax is when you are the busiest.
1968: The best time to relax is when you don’t have time to relax.
1973 Jan: The best time to relax is when you don’t have the time.
The earliest match located by QI appeared in the syndicated newspaper column of Sydney J. Harris in October 1954. Boldface added to excerpts by QI:[ref] 1954 October 26, Chicago Daily News, Strictly Personal: You’re Too Busy?, Time To Relax by Sydney J. Harris, Quote Page 18, Column 6, Chicago, Illinois. (GenealogyBank) [/ref]
The time to relax is when you don’t have time for it; when you get the time, you are generally too exhausted to enjoy it. The way to relax (I have found, at least) is to spread it out during the week, so that the tensions don’t snap into listless apathy at the weekend.
Below are additional selected citations in chronological order.
In November 1954 columnist Beulah Schacht printed a variant saying:[ref] 1954 November 28, St. Louis Globe-Democrat, Section: Globe-Democrat Magazine, Take It From Beulah by Beulah Schacht, Quote Page 22, Column 3, St. Louis, Missouri. (Newspapers_com) [/ref]
The world is certainly cluttered up with a lot of good advice which is impossible to take. For example, this bit which came through the mails: “Watch yourself! The time to relax is when you’re too busy to relax.”
Schacht disclaimed credit for the advice and actually indicated that she disagreed as shown in the following sentence. The slang phrase “gold brick” refers to someone who shirks duties and loafs:
You may stay healthier longer by following it, but who wants to be the healthiest gold brick in the world?
In 1960 a journalist in a McHenry, Illinois newspaper published this instance:[ref] 1960 November 17, The McHenry Plaindealer, Sports by Earl Walsh, Quote Page 4, Column 2, McHenry, Illinois. (Newspapers_com) [/ref]
The best time to relax is when you are the busiest.
The columns of Sydney J. Harris were sometimes reprinted. For example, in 1964 the “Greensboro Daily News” of North Carolina reprinted the 1954 column. Thus, the remark achieved further circulation.[ref] 1964 September 8, Greensboro Daily News, Taking Time To Relax by Sydney J. Harris, Quote Page 8A, Column 5, Greensboro, North Carolina. (GenealogyBank) [/ref]
In 1968 Evan Esar published the collection “20,000 Quips and Quotes” which included another instance:[ref] 1968, 20,000 Quips and Quotes by Evan Esar, Subject: Relaxation, Quote Page 669, Doubleday, Garden City, New York. (Verified on paper)[/ref]
The best time to relax is when you don’t have time to relax.
In 1973 Sol Margoles who sold tires in Springfield, Massachusetts printed an advertisement with the following instance:[ref] 1973 January 10, The Springfield Union, Sunny Side Up by Sol Margoles and BFGoodrich Your Radial Tire People (Advertisement for Sol’s Tire Service), Quote Page 35, Column 3, Springfield, Massachusetts. (GenealogyBank) [/ref]
The best time to relax is when you don’t have the time.
The connection to Harris was not forgotten. In 1977 the collection “Quote Unquote” compiled by Lloyd Cory included the following entry:[ref] 1977, Quote Unquote, Compiled by Lloyd Cory, Section: Relaxation, Quote Page 272, Published by Victor Books: A Division of SP Publications, Wheaton, Illinois. (Verified on paper)[/ref]
The time to relax is when you don’t have time for it.
Harris also received credit in the 1997 collection “The Forbes Book of Business Quotations”[ref] 1997, The Forbes Book of Business Quotations: 14,173 Thoughts on the Business of Life, Edited by Ted Goodman, Topic: Leisure, Quote Page 503, Column 2, Black Dog & Leventhal Publishers, New York. (Verified with scans)[/ref] and the 2004 compilation “Oxymoronica: Paradoxical Wit and Wisdom from History’s Greatest Wordsmiths” from Mardy Grothe.[ref] 2004, Oxymoronica: Paradoxical Wit and Wisdom from History’s Greatest Wordsmiths by Mardy Grothe, Chapter 10: Oxymoronic Advice, Quote Page 163, Publisher HarperCollins Publishers, New York. (Verified on paper)[/ref]
In conclusion, Sydney J. Harris shared this saying with his readers in 1954, and he is the leading candidate for originator. During the ensuing decades multiple variants have appeared.
Image Notes: Illustration of multiple clock faces from geralt at Pixabay. Image has been cropped and resized.
(Great thanks to Nigel Rees whose inquiry on behalf of Beth led QI to formulate this question and perform this exploration.)