This was one systematic review, and only four of its 20 included studies directly reported how long habit formation took. What the University of South Australia review examinedBen Singh and colleagues searched six academic databases for experimental studies of health-related habits. Among those who successfully formed a habit, the modelled time to reach 95 per cent of peak automaticity ranged from four to 335 days, with a median of 59 days. It was the far end of a wide individual range produced by a model, while 59 days described the midpoint among successful cases in that particular study. Habit formation was modelled as a rising curve.