Earlier I wake up, more productive I can be. From productivity perspective around 5 am would be the best time for me to get up. I don't know what's the magic about those morning hours, but somehow I manage to get more done than if I work some number of hours in evening, for example. Maybe it's because other people are away at early morning.
Unfortunately I am evening person, with some kind of sleeping disorder (insomnia). I can postpone sleeping as much as I like, but if I try to sleep at 22 for example, it's just rolling at the bed until 2 am or something like that. Time I wake up has nothing to do with time I can fall sleep again. I have medication (melatonin) for that problem, but it's only a slight help.
Total GTD newbie, better with the GTD theory than implementation.