yup here in Ontario Canada its 3 days. if ur at 120 mg and miss 3 days you start all over from 20-30 mg......I in fact know several people who use morphine and hydromorphone etc IV, and they have scripts for low dose methadone, like 20-30 mgs. they go once every 3 days. the reasoning being that they can continue to shoot dope, and if they cant get any they have a decent little methadone fix to tide them over. also in case of incarceration. if they get arrested and put in jail they wont have to face full on withdrawal since they legally have an Rx for 30 mg of methadone. and ya they just go in monday, thursday, saturday type thing.....if they cant get dope sometimes you see them there a whole week straight then they drift off again