Does it take a person to perform an activity or routine 21 times for become new habit?

While popularized by a misreading of a 1960 book, the idea that it takes 21 days to form a new habit has been widely debunked. The time it takes to form a habit varies depending on the individual, the habit and other factors, but it can take much longer than 21 days. Research suggests that it can take anywhere from 18 days to 254 days for a new behavior to become a habit, and the average is 66 days.