Do your hardest work at your best hour
Most people think more clearly at certain times of day, and doing your hardest work at your peak can make a real difference. In a 1993 study, Cynthia May, Lynn Hasher, and Ellen Stoltzfus found that older adults, who mostly preferred mornings, remembered more when tested in the morning, while college students, who mostly preferred evenings, did better later in the day. Researchers call it the synchrony effect: performance is better when the task lines up with your best time.
How many times have you sat down to write a proposal at 3 p.m. and stared at the screen for 40 minutes? Then, the next morning at 8:30, you knocked it out in 25.
It wasn't the proposal. It was the hour.
What the research says
In 1993, Cynthia May, Lynn Hasher, and Ellen Stoltzfus tested memory in two groups: older adults and college students. First, they asked everyone when they felt sharpest. Most of the older adults were morning people. Most of the students were evening people.
Then they tested both groups at different times of day. The older adults did better in the morning. The students did better in the late afternoon. When people were tested at their "off" time, their performance dropped.
This is called the synchrony effect. Researchers have found versions of it in memory, focus, and problem-solving since then. When the task lines up with your peak time, you do better. When it doesn't, you work harder for worse results.
Why business owners ignore it
Most of us schedule by what's urgent, not by when we're sharp. So we spend our best morning hours answering email and putting out fires. Then we try to do the strategic thinking, the writing, or the sales calls in the afternoon slump.
That's backwards. And it's why so many important projects feel so hard. Urgent tasks are great at stealing your best hours, which I wrote about in Urgent isn't the same as important.
How to find your best hour
Track your energy for one week. A few times a day, rate your focus from 1 to 5. Note the time.
Look for your peak. For most people, there's a two- to three-hour window where the numbers are consistently higher.
Look for your slump. There's usually a dip too. For a lot of people it's early to mid afternoon.
Notice your real-life limits. If you have kids in daycare or school, your peak might not match your available hours. That's okay. Work with the best overlap you've got.
How to use it
Peak hours: Deep work. Writing, planning, strategy, sales calls, anything that needs your best brain.
Slump hours: Admin. Email, scheduling, invoices, organizing files.
Recovery hours: Creative but low-stakes work. Brainstorming, reading, outlining.
And protect your peak like it's a client meeting. Put it on the calendar. Close email. Silence your phone.
If your peak only gives you short windows, that still works. Use them for the most important piece, and save the rest for later. That's the idea behind building your business in 20-minute scraps.
What it looks like
One client of mine is sharpest from 8 to 11 a.m. She was spending that time on email and social media every single day. So I had her flip it. Now her mornings are for writing and sales calls. Email waits until after lunch, when her brain isn't doing much else anyway.
She told me her week feels about 30% lighter even though she isn't doing less. She's just doing the hard things when they're easier.
If you want help building a week that fits how you actually work, here's how I coach.
Frequently asked questions
What is the synchrony effect?
The synchrony effect is the finding that people perform better on mental tasks when they're done at their preferred time of day. May, Hasher, and Stoltzfus described it in a 1993 study.
What is the best time of day to work?
It depends on your chronotype. Track your focus for a week to find your peak hours, then schedule your hardest work for that window.
What should I do during my afternoon slump?
Use low-energy hours for admin tasks like email, scheduling, and invoicing, and save focused, high-stakes work for your peak hours.
Sources: May, C. P., Hasher, L., & Stoltzfus, E. R. (1993). Optimal time of day and the magnitude of age differences in memory. Psychological Science, 4(5), 326–330.
