Matthew Hutson is a freelance science writer in New York City and the author of “The 7 Laws of Magical Thinking.”

Each year, more and more people work on their own time. From 2010 to 2014, the number of independent contractors in the United States grew by 11 percent, according to a 2017 report on the “gig economy” by the Aspen Institute. As a freelancer, I find that the greatest hardship isn’t getting enough gigs but managing my schedule. Some challenges are familiar to company employees, such as deciding how many hours to put into any part of a given task, but others are more acute for those unswayed by the rhythms of the office. What time to get up, how many breaks to take, when to start a new project. (Plus the perpetual dilemma that every day is a vacation day — and every day is a workday. Weekends hold little significance.)

Given the motivational mind games inherent in freelancing, a manual for structuring my day might be handy — not that I would necessarily adhere to it. In “When: The Scientific Secrets of Perfect Timing,” Daniel H. Pink doesn’t reveal every secret about perfect timing — how long should one wait before following up on an unanswered email? — but he does give a cheat sheet on when to work, sleep and play, useful for both freelancers and those beholden to bosses. His life advice covers arenas from work to marriage to sports, and time spans from milliseconds to decades, in a volume that Pink, a business author and former politics and policy wonk, calls not a how-to book but “a when-to book.”

“When,” by Daniel H. Pink (Riverhead)

Some tidbits: Exercise in the morning to keep a routine or boost your mood; exercise later in the day to perform better and enjoy it more. Before marrying, date for at least a year and finish your education. The best time to switch jobs for a salary bump is after three years (once you’ve garnered some skills) but before five years (so you’re not too tied to your company).

The first 40 percent of the book focuses on daily patterns. We read about circadian rhythms, seeing graphs depicting two peaks in the average person’s mood, one around noon and one around 9 p.m. Performance on tasks requiring analytic reasoning tends to slump in the afternoon (hence afternoon coffee breaks). Creative insight, however, tends to peak during these diurnal doldrums. Night owls have different biological rhythms, so “what ultimately matters,” Pink writes, “is that type, task, and time align.”

Alignment can be a matter of life and death; medical errors increase in the afternoon. But taking breaks can help. When surgical teams pause to regroup before a procedure, patients benefit. Students score higher on tests after recess. Judges become less harsh after a snack. The best breaks, research suggests, are active, social, outside and fully detached from work (no lunching at your desk). Even better are naps — 20 minutes or less, preferably with a shot of coffee just beforehand. Pink has become a convert to the “nappuccino.”

Next Pink presents chapters on beginnings, middles and endings. Research indicates the importance, for example, of temporal landmarks: the beginning of a new week or semester or year. People see them as chances to start fresh and are more likely to, say, visit the gym on these dates. Pink suggests that individuals or teams mark additional dates as somehow significant to inspire escapes from ruts. Pink also notes how we can become perpetual victims of bad starts, as when a child is born into poverty or a graduate enters the job market during a bad economy. He suggests offering extra support to people in these circumstances.

We suffer midpoint slumps not only in afternoons but also midlife. Such “crises” are not actually as acute or existential as commonly espoused; nonhuman apes show the same gradual decline and recovery of happiness in middle age, suggesting an unknown biological cause. At other times, people become more motivated at midpoints, particularly if they’re halfway to a deadline with little to show or if they’re down by one point at halftime.

We’re also motivated by endings; people sprint before deadlines are up and are more likely to run a marathon — or attempt suicide — at ages that end in 9. We strive, sometimes unsuccessfully, for meaning near conclusions. Pink writes that endings help us not just “energize” but also “encode” (last impressions are lasting impressions), “edit” (we prune social networks near graduation or death) and “elevate” (we savor final bites and feel poignancy when experiences come to a close).

Finally, before a brief encapsulating chapter, the book discusses interpersonal synchrony, necessary for productivity, well-being and even survival. Pink writes that we must synch “to the boss, to the tribe, and to the heart.” That is, we need an external pacesetter (a clock, choirmaster or coxswain), a communal bond (established through codes, clothes or contact) and a higher mission. Given the physical, mental and moral benefits of temporal melding with others, Pink writes that “choral singing might be the new exercise.”

Pink doesn’t go especially deep into any area. He skips around between disparate topics, he notes the use of research assistants, and he has a tic of quoting study findings rather than putting these mostly pedestrian passages in his own words, a habit that gives the vague impression of lacking mastery of the material (or, more generously, of carefulness).

But the book doesn’t aspire to comprehensiveness or a bold new theory of humanity’s relationship with the temporal dimension. As he says, it’s a “when-to” book, and each chapter is followed by a “Time Hacker’s Handbook.” These might be the most useful portions. We learn things like the ideal morning routine; common improv games for team building; and how to start a new job, avoid a midlife slump and end a vacation. The book is well-structured and goes down easy, with concise summaries often packaged with alliteration (type, task, time). No surprise, given that Pink wrote speeches for Al Gore.

The book starts with a questionable lesson, using the sinking of the Lusitania to suggest that the captain’s bad decisions “were bad because he made them in the afternoon.” A bit like pinning a particular hurricane on global warming. But consistently applying the principles laid out in the book could have dramatic impacts on one’s life and on society.

The most general advice comes at the end, when Pink recommends that we not live in the present, “as so many spiritual gurus have advised,” but integrate the past, present and future; various studies suggest that nostalgia increases life’s meaning and that we make better plans when we identify with our future selves. I think living in the present has its place (and time) too, and these few pages could be expanded into a book of their own, possibly with more Heidegger. But the big-picture musings are a nice prompt for the interested reader at the finale of an otherwise practical book.

I’ll leave you with one of my favorite quotes on time, allowing the late, great thinker Douglas Adams to bring metaphysics full circle to freelancing: “Time is an illusion. Lunchtime double so.”

The Scientific Secrets of Perfect Timing

By Daniel H. Pink

258 pp. $28