There are four study schedules available for the ACT: the One Week Schedule, the One Month Schedule, the Two Month Schedule, and the Three Month Schedule. As you can probably guess, the main factor in deciding which schedule to choose is how much time you have to study.
The one-week and one-month plans have daily instructions, and the two- and three-month plans are structured on a weekly basis. Otherwise, the material covered is essentially the same. We recommend that you 'round down' based on how much time you have before your exam. For example, if you have one and a half months to study, choose the 1 month plan. Then you can use any leftover time for extra review.
Happy studying! :)