As long as it take. Most say you never stop improving. I think you should just keep doing it ayt the level that you need.
Well, I think that is infividual, because people are not the same, and for me I think will need more time because I just can not relax that easly.
I'm not sure if anyone masters meditation. It is an ongoing process with ebbs and flows. Meditation is a companion and similar to a relationship. You invest and the relationship is fulfilling. If you don't nurture the relationship you feel the effects.
Meditation is not something you are aiming to get right and master, it is a process. Some days you may find your practice will go very well and other days you may have constant thoughts coming into your mind. What matters is not whether you kept your mind blank etc but the practice of coming back to the breath, viewing thoughts as detached thoughts, accepting then for that they are and coming back to the breath. You may meditate for years but your practice may never be perfect, meditation is not an end goal but a journey and a process to explore and enjoy.
Elze Rio Z.
The first time you sit down and try to stay present with your breath you are mastering meditation. Meditation is not about being good at it, it’s about the process!
Forever. We are far from mastering anything related to our unconscious mind. The possibilities are infinite if you keep dragging it.