how many days in a row makes a habit
Streak target. This is how many times in a row you must do the habit before you can consider it installed and check it off your list. (Keep in mind that, on average, it takes 66 days to install a habit. I typically round this up to at least 70 for good measure.)
This column will change your life: How long does it really take to change a habit? Everyone knows that it takes 28 days to develop a new habit, or perhaps 21, or 18, depending on who you ask; anyway, the point is that it's a specific number, which makes it sound scientific and thus indisputably true.