A month may seem like a short period, but 30-day rehab is a real start for serious changes. It depends on the person’s willingness to work on themselves. This concept is explained very well in the article https://unitedrecoveryproject.com/rehab-blog/30-day-rehab/  . They tell you how the program is built: intensive work on habits, emotional stability, and planning support after discharge. If you are serious, in 30 days you can lay a very solid foundation for further recovery.