The time it takes to form a habit really isn’t that clear-cut. On average, it takes more than 2 months before a new behavior becomes automatic — 66 days to be exact. And how long it takes a new habit to form can vary widely depending on the behavior, the person, and the circumstances. In Lally's study, it took anywhere from 18 days to 254 days for people to form a new habit....

Is what I found from Google. 

I wouldn’t dare to google the reciprocal question — “how long does it take to break a habit” because i am afraid of what will show up. 

But I think I already know my answer.... 

Calling you for everything is still something I find myself doing. 

I have to break my heart over and over again re-realizing that when I dial your voice won’t be on the other end. 

I know you never left me and you’re always with me - but I miss you like crazy.