There are 30 content lessons (plus a bonus lesson), and it’s reasonable to complete one lesson per day.
That said, it’s an online course. You can take it at whatever pace suits you. If you had some navy seal-like discipline, you could do 4 to 5 lessons a day and finish it in a week (not recommended, though), or you could do one lesson every three days and finish it in 90 days. Entirely up to you.