Circadian rhythm is your body's internal clock. It's how you can keep track of time naturally, without ever needing to know what time it actually is.
When you learn to observe and understand the your natural flow, you can align your activities and schedule accordingly. This not only helps with time management but it also helps with mind management and energy management.
If you want to increase productivity, then invest some time "sharpening the axe" that is your natural rhythm.
"If I had six hours to chop down a tree, I'd spend the first four sharpening the axe."
—Abraham Lincoln
Many people experience the ups and downs of energy on any given day. This is their natural circadian playing out.
If you know yours, and align with it, you can schedule your days in accordance with your rhythm. For example, if you're more productive in the morning, then you can schedule your most important things before 9am.
On the other hand, if you're a creative, maybe you do your best work at 2am long after everyone else has tucked in.
Can you see how this could impact your productivity?
Many productivity "gurus" will tell you to wake up one hour earlier. But if you're the creative who does his best work in the middle of the night, you don't need to wake up one hour earlier, you actually need to go to sleep one hour later.
If your Knowledge Gap includes your circadian rhythm, then you'll want to spend some time paying attention.
Start taking notes throughout the day about how you're feeling. Do a check-in with yourself every couple of hours, or after particular events.
For example, what time does your body naturally wake up if you don't set an alarm? How do you feel right after rising?
When do you first start getting hungry? Early morning, mid-morning, or maybe it's closer to noon? How do you feel after you eat?
Each and every individual cell that makes up your body has a circadian rhythm. This effects mental alertness, your digestion, heart rate—almost anything you'd get tested at the doctor's office has a natural cycle.
If you can learn what yours is, you can start building your day around it. Aligning your activities with the natural cycles of your individual energy allows you to drop into flow more easily (and stay there).
The suggestions outlined above are enough to get you started. But if you want to take it a step further, then spend 10 minutes taking an assessment called the AutoMEQ (Automated Morning-Eveningness Questionnaire).
It's a quick survey that asks you some generalized questions. Take it with a grain of salt, and use it as a baseline for understanding your body's natural rhythms.
After a few weeks of testing, you'll have a good idea of how (and when) your cycles work throughout the day.
Related: Schedule Your Day with the Ocean's Tides