Yoga began with the first person wanting to be healthy and happy all the time.
[T]he period between four and six in the morning is called the Brahmamuhurta, the Brahmic time, or divine period, and is a very sacred time to meditate. (140)
When even one virtue becomes our nature, the mind becomes clean and tranquil. Then there is no need to practice meditation; we will automatically be meditating always. (151)