How to Form Healthy Habits with the "66 Day Rule"

Chances are, you started this year with hopes of adding some habit to your daily routine, like an earlier wake-up time, or a consistent exercise cadence, or, at long last…a nightly flossing regimen. (You know who you are, one-third of American adults.)

We’re now about month into 2024, so it’s understandable, if you’re still smashing the alarm all morning, sitting around all day, or finding popcorn kernels in your molars, to assume that you’ve failed. Habit-forming simply isn’t for you — at least not when you’re trying to form healthy ones.

But that mentality is rooted in our annual amnesia to the stochasticity of resolution-making. Every year, all at once, we swear we’re going to do a bunch of new, amazing things; and when we can’t stick to them, we label ourselves quitters. (There’s even a day for it.)

This mental disconnect is also related to our assumption that habit-forming should be an immediate transformation. Pop psychology books released in the back half of the 20th century advanced the notion that new, desirable habits generally took around three weeks to develop. But the “21 day thesis” — which would suggest we’ve all failed, here at the end of January — has since been debunked.

Why Are People Making 1,000-Day Calendars?

It’s time to start thinking about September 2026. Allow us to explain.

How Long It Actually Takes to Form Habits

So. How many days does proper habit formation actually take? Think: a little over three times longer, at 66 days. And that’s only the average. Habit forming tends to appear to researchers in a broad range — anywhere between 18 and 254 days is a reasonable estimate for how long it will take you to pick up (and stick to) a fresh routine.

Why such disparity in timing? Well, because there’s a wide disparity in habits. Peeling a clementine once a day is easier than meditating for a half hour before bed. It might feel oddly mollifying, though, to learn that you probably can’t pick up your resolution in the span of a month. It might take until March…or all the way until September.

As everyone’s interests, attitudes and schedules are different, there’s no way to know if forming a habit is taking you “too long,” or not — you simply have to rely on your own intuition, and recognize when an effort is becoming a chore. If it’s weighing on your mental health, consider shelving it for later, or diverting your energy elsewhere.

It’s also important to remember that even once it seems like you’ve officially adopted a habit, there will be “slip-ups” — times where you don’t check it off in your little planner. Maybe you forget to do whatever it is, or just can’t be bothered. That’s completely okay. As Arnold Schwarzenegger, one of the best habit-formers out there, has been known to say: “Don’t let perfect be the enemy of possible.”

If this month didn’t go as planned for you, fine. Forget those three-week deadlines. Your 66 days (or 254, or whatever it takes) starts now.