Every moment is a prayer.

Watch the following video from 55:50 to 58:28.

When every step becomes a prayer, when every breath becomes a prayer, when each moment of walking, driving or eating becomes a prayer, you don't need to set aside time for praying. Because all of your daily life is devoted to a practice of praying. 

And therefore, the answer to this question would be that we should not divide the time in that way. Time for walking, for eating, for living in forgetfulness, and time devoted to mindfulness, concentration, insight and prayer. That is not the way we see it. Every moment of our daily life can be a moment of prayer, of meditation, of practice. And we need to be trained in order to do so. 

There are moments we do not realize. We are pulled away, carried away by our worries, our anger, our projects. And we waste our life because of that. Nobody wants to waste his or her life. We want to live our life deeply. And the only way is to pray. And the only way is to generate the energy of mindfulness, concentration and insight. And then, we can live very deeply every moment of our daily life. And our life is a life of practice, is a life of prayer. There is no distinction between the time of praying and the time of living, or non-praying.

We need to live in mindfulness, concentration and insight 24 hours a day in order to be a full-time Buddha.

(Cf.) http://www.amazon.com/dp/B014NYEP04

Meditation Hall at Plum Village