A 4.30 or 5.30 wakeup routine where one goes to sleep between 9.00 and 9.30 pm is one that gives time for fitness, a chance to so something for oneself before daylight and before the world wakes up. This report is in Style in WSJ when it should be in the Health and Wellbeing section. Rising early is part of yoga tradition for meditation in India where it is called Brahmamurta (time of Brahma) generally between 3.30 am and 5.30 am in the early morning. It is the time of the Creator of the universe, Brahma.
It is the best time for meditation on Ram, Brahman, on Christ or the Buddha. It can also be used for creative activity and for work that require concentration and clarity of mind. When the whole world sleeps the sage is awake, says the Bhagavad Gita. In Christian churches this is also the time for early morning prayer.