Saturday night, I tried a half-pill. I still got sleepy faster than expected, but I woke up a bunch of times. I mostly managed to doze back off again. The effect was pretty much the same on Sunday night. Maybe, overall, I slept better?
I am thinking of looking into timed-release melatonin. The making-me-sleepy part works well; if it could work in the wee hours, that would be awesome. If it was already in my system at 4 am, maybe it wouldn't take an extra hour to kick in.
Got writing done regardless. I made sure that happened. About 2000 more words in, AND I have broken my draft into two-and-a-bit chapters.