"It's the only time we're alone"

Here's the practical case for the late hour. The children are down. The phones are off. The evening is the one stretch of the day the two of you have, and if the row can't happen then, when?

The late hour is the only slot and it's the worst one, and both of those are true, and the answer is to make another slot rather than to use the bad one. Chapter 21 is about the resume time, and the short version is that ten minutes at eight, before the children are properly up or after they've gone, is worth more than three hours at midnight, because the ten minutes have the two of you in them and the three hours have the late brain.

An earlier book in this series is about staying up late for time of your own, and its point is that the need for that time is real and the hour it's taken from is the problem. The same applies to time as a couple. You need it. Taking it out of sleep, at the low point of the day, in the form of an argument, is the worst way to have it. Most couples who look honestly at their week can find ten minutes in it that isn't midnight. Saturday morning before anyone's up. The walk after Sunday lunch. The ten minutes after the children are down and before the television goes on, at half past eight, when the low hour hasn't quite arrived. Those are slots, and they're slots for the conversation the row was trying to be.

There's a thing worth noticing about the late slot. It's the only one because it's the one that's left when nothing else has been arranged, and things that happen in the leftover slot happen badly. An argument that's had to wait until eleven to happen is an argument that's been building since the dishwasher, and building is not the same as thinking. If the two of you had a standing ten minutes on a Sunday, a fair amount of what becomes a row at eleven would have been a sentence at ten past twelve on Sunday, and the dishwasher would have been the dishwasher.