Here's what a first week of phone-free evenings actually looks like, rather than how it gets described afterwards.
Before you start
Decide the hour and tell one person. Not for accountability theatre — just so that when you don't answer at 8.15 nobody thinks something's happened.
Then put the thing you're going to do in the room before the hour starts. This is the single step people skip and it's the one that decides the week. If at 8pm you have to go and find something to do, you will find your phone, because it's closer.
Night one is fine
Novelty carries it. You'll feel briefly pleased with yourself. You may find the hour goes quickly and think this was easier than expected.
It was. It's night one.
Night two is the real one
Around twelve minutes in, something like irritation arrives. Not boredom exactly — a physical restlessness, the sense that you are wasting time, that there's something you should check.
Almost everyone quits here, and almost everyone reads it as evidence that they can't do this. It's the opposite. That feeling is the withdrawal from a day of constant small inputs, and it lasts about ten minutes if you don't act on it. It will be shorter on night three and mostly gone by the end of the week.
You don't need to do anything about it. Sit in the chair and let it be unpleasant for ten minutes.
Night three or four, you'll break it
Something legitimate will come up. A message you genuinely need to answer, or you'll look something up for a reason that is completely reasonable, and then it's 9.20 and you're still holding it.
Nothing has gone wrong. Do the hour again tomorrow. The instinct to declare the week a failure and restart cleanly on Monday is the instinct that has killed every habit you've ever tried; the fix is just to carry on from the middle.
By night five something shifts
Not transcendence. Something smaller and more useful: the hour stops requiring effort and starts being the part of the evening you're looking forward to.
Usually people notice it through sleep first. Then through the fact that they can remember what they did that evening, which — if you think about the last month of evenings — is not a given.
The weekend will wreck it
Different rhythm, other people, no fixed dinner time. The hour will not happen on Saturday and probably not Sunday.
Fine. Weekdays only is a perfectly good version of this. Trying to hold it seven days is how you end up holding it zero.
What to do in week two
Nothing new. Don't extend it to two hours, don't add the morning, don't build a system.
The same hour, the same chair, the same time, until it stops being a thing you're doing and becomes a thing you do. That takes longer than a week and it's extremely boring to describe, which is why almost nobody writes this part down.