We recommend that beginners start with a 3- to 5-minute meditation once a day. As that starts to feel comfortable, you can either extend your meditation time to 10 or 15 minutes, or you can add a second 3- to 5-minute meditation each day.
Many experienced meditators have worked up to 20-minute meditations every morning and evening, but you can move in that direction at your own pace, knowing that even just a few minutes of daily meditation provides numerous benefits.