Surprisingly, with two small kids, I only reinforced my night-owl habits. The rhythm we settled at is simple: my wife - a natural early bird - handles the early morning while letting me sleep in a little, and I - a natural night owl - stay up late, effectively covering for anything that happens between 23:00 and 03:00, so that it doesn't wake her up.

It's a bad system in so many ways, but we can't seem to make anything else work. And we know from experience that both of us getting enough sleep is the foundation on which everything else stands.

We did shift-sleep for the early weeks for all three kids (all ours were sleeping through the night by 3ish months, so it was never that long we had to do it, though) and I can't imagine doing it any other way. Couples who both get up for every event out of some apparent sense of either solidarity or resentment are just baffling to me. WTF, so you're both constantly running on like zero REM sleep? Jesus, that's like doing it on hard mode for no good reason.

The way we did it, we both got about six uninterrupted hours every week night, so it really wasn't that bad. Then alternate sleep-in days on the weekend, and you even get one really good 8+ (hell, sometimes 10 or more) hour sleep per week. Could have maintained that schedule much longer than we had to, really was totally manageable, if not exactly fun.