In a DNA test I made I came up being more a night than a morning person. It also matched a questionnaire I made: https://en.wikipedia.org/wiki/Morningness–eveningness_questionnaire
Apparently, knowing this and acting accordingly can help you become more productive and less depressed throughout the day. However, I find that it contradicts the Gurbani recommendation of waking up and meditate during Amrit Vela, because if I follow the scientific advise I should wake up after sunrise. What do you think? Please comment.