I’ve tried this so many times and while it lasts I love it. I feel like I haven’t missed anything, I seem to need less sleep.
I live only 10° from the equator (Vietnam) so 5AM is only beginning to show a lightening sky, every day the same. 6AM is quite light out and most of the country is awake, the streets are noisy.
But it never lasts. I’ve never been able to maintain it more than two weeks. It’s hard to stop playing my guitar (classical, no amplifier) or reading. I’ve seen 5AM from the other side a lot more often than awakening.