I've gradually also had to shift my starting time at work later. Which means staying later. Which means getting home later. Which means eating dinner later. Which means sitting down in the evening to relax later. All of which means bedtime comes sooner.
Finally sick of the whole vicious cycle, yesterday I decided to start getting up early again. However, rather than pick an arbitrary start time, I wanted to make the change empirically. Given what I've learned about sleep cycles, there's a natural rhythm, the end of which flushes out the sedatives your body naturally produces to keep you from moving too much during the dreaming phase. If you wake up at the end of one of these ~90 minute cycles, you are able to get up fairly easily. However, if you wake in the middle of a cycle, you'll feel pretty dang groggy until your system clears out.
Unfortunately, I think part of what broke the habit for me was that my schedule left 5:00am as being in the middle of a cycle instead of at the end of one. I'd get up at 5:00 and have to fight to wake up. Given my aversion to mornings in the first place, that was a combination punch that knocked me out.
However, over the last few weeks, I'd noticed that, during my normal short wakeups during the night, I was seeing consistent times on the alarm clock. Those times matched up with about 90 minute-divisible times from when I went to bed +/- 20 minutes for when I fell asleep. I rarely sleep through the night and usually wake up 2-3 times, though only for a couple of minutes.
Figuring that I'd eventually want to get back to early mornings, I made a note on a pad on the nightstand for when we went to bed and the wakeup time nearest 5:00am. I never once saw anything within a half-hour of 5:00am, which made it abundantly clear why that time wasn't working for me. However, I did see a pretty consistent pattern: 4:24, 4:28, 4:22, 4:34, etc.
So, yesterday morning, I set the alarm for 4:30am and muttered under my breath about the insanity of that time (which I used to say should only come once a day). I woke up at 4:29 and rolled over to see the clock flip and the radio turn on. This morning, I rolled over at 4:27 and just shut it off and got up.
Yesterday, I felt 10x better than I've felt in months. I was alert all day, had better focus and the day was SO much longer. This morning I'm wide awake and have none of the morning "grog" that I'd gotten used to again. I remember why I was getting up early before and really need to stick with this.
It's become clear to me, based on my own methodical look at this problem in my own life that the *duration* of the sleep isn't as critical for me, at least as the rhythm. There seems to be some science to back that up as well. I feel WAY better on 4 even cycles equaling 6 hours than I do on 8 hours in 5 1/3 cycles.
I suspect that the conventional wisdom of "you need to get 8 hours of sleep" is targeted at a 7.5 hour sleep time (5 cycles) and padded for the time to fall asleep. However, I also know that if I go 6 or 7 cycles, I'm more tired than if I go 4, so there's something less than straightforward about this whole science.