Hi there Junglesgal and welcome to the community
It initially takes approximately 8 minutes to entrain to the desired frequency/brainwave state. As Itlandm stated, over time, instead of taking 8 minutes, it can take less and less time (even within a few moments) once you become familiar with resting in these calmer states. In the beginning you may experience the peace and tranquillity for only seconds, or it may last for many minutes. Even just a few moments in this state carries with it tremendous benefits. As you progress, this feeling of peacefulness will follow you throughout your normal daily activities for longer and longer periods of time. Whatever the duration of time you remained in tranquillity, your mind and nervous system were afforded some much needed rest.
Your body will have shut down its production of stress hormones, allowing those already present in your system to dissipate. Peace and calm will begin to assert themselves in your life. In short, you will reap the rewards on every level of your being, and these rewards will carry with you out into your daily life. Meditation is cumulative, therefore, if you have 20 minutes per day, that’s great. When you reach these beneficial states as I and others here do in just a few moments (or say a minute) then even 5 minute mini meditations are extremely valuable.
Here’s a link to some valuable information about meditation and entrainment which has helped many people here:-
Principles of Meditation & Entrainment
Hope this is of help and wish you much peace and joy
