Screen Time on a Mac is not Screen Time on an iPhone. Here is the list.

You opened Screen Time on the Mac and it looks the same, which is the problem.

Same pane, same week in columns, same little clock beside Downtime. Which is why almost everybody who asks does Screen Time work on a Mac gets told yes, and finds out about eleven days later that yes was doing a great deal of work in that sentence.

It does work. Roughly two thirds of what you set on the phone comes across intact. The rest turns up, looks around, and finds nothing to stand in front of. This is the list of which is which, in the order the settings appear in the pane, so you can read it with System Settings open beside you.

Two switches have to be on before any of the rest is true

Do these first. With them off you do not have one system with gaps in it. You have two unrelated machines keeping separate diaries and neither of them knows the other exists.

1. Turn the report on, on the Mac. Apple menu, System Settings, Screen Time in the sidebar, then App & Website Activity, then Turn On App & Website Activity. Nothing further down the pane does anything at all until this is on, and on a Mac you have never used it for, it is off.
2. Turn on Share across devices, in both places. On the Mac it is near the bottom of that same pane. On the phone it is Settings › Screen Time › Share Across Devices. Both devices, same Apple Account, or it does not count.
3. Set the Screen Time passcode on the Mac. It is called Lock Screen Time Settings there, and it wants four digits. Do it before you go any further, because two of the settings below this line do not appear until a passcode exists.

That third step is the one people skip, and it costs them the whole setup. On a Mac, Block At Downtime is a checkbox that is only available while you are using a Screen Time passcode. Without one, Downtime greys things and asks nicely. With one, Downtime is a door.

The switch that carries everything is labelled as if it carries nothing

Read the line underneath Share across devices on the Mac. It talks about reports, and about including time spent on your other devices. It reads like an accounting feature. So people who want a limit rather than a diary look at it, decide they do not need better statistics, and leave it off.

Apple's own page about App Limits on the Mac says the other half out loud: the limits apply to that Mac and to every other device signed in with Screen Time and this switch turned on. It moves rules, not just numbers. Its label mostly mentions the numbers.

If you have run Screen Time on both machines for a year without this on, you have not had one system with gaps. You have had two.

What crosses whole

These are the parts that mean the same thing on both machines, because they are built out of something both machines have.

Downtime, because a time of day is a time of day.

Ten at night is ten at night on anything you own. Downtime is the only rule that needs nothing from the device except a clock, which is why it is the one that survives the crossing without losing anything. Set it once, on either machine, and the hour before bed is covered on both. For the specific problem of the evening, this is most of the available win, and it is free.

The week, added up once instead of twice.

With the switch on, you stop having a phone number and a laptop number and start having a number. It is a worse-feeling number and a much more honest one. It is also the only way to find out whether the limit you set on your phone actually gave you an hour back or simply moved it two feet to the left, which is the question underneath you blocked it on your phone, so you opened the laptop.

The passcode, and the escape hatch behind it.

When a limit runs out on the Mac, a window appears with OK and Ignore Limit, and behind Ignore Limit are the same three offers you already know from the phone: one more minute, remind me in fifteen minutes, ignore the limit for today. Set the passcode and tick Block at end of limit and that window becomes a request for four digits instead. Same logic, different frame around it.

Content and privacy restrictions, which now even share their headings.

Both systems group these the same way, which is new enough that most guides are still describing the old arrangement. On the Mac it is System Settings › Screen Time › Content & Privacy, and inside that you get App Store, Media, Web & Games, then Store Restrictions, then App & Feature Restrictions. The setting that closes the delete-and-reinstall loop on a phone has a counterpart under App & Feature Restrictions here, alongside the one for installing apps. Communication Limits crossed too, and covers calls, FaceTime, Messages and your iCloud contacts on both.

What crosses and finds nothing to hold on to

A limit on an app that has no Mac version.

Instagram has no Mac app. Neither does Reddit, or Threads, or Snapchat. Your ninety-minute limit arrives at the laptop in perfect condition and there is simply no door for it to stand in. Nothing is being ignored and nothing is broken. The rule is standing in an empty corridor being extremely professional about it.

Website limits, which cross and then stop at Safari.

Start with the good news, because it is genuinely useful and almost nobody knows it is there. You can name a website in an App Limit on the Mac. System Settings, Screen Time, App Limits, Add Limit, and at the bottom of the list of apps and categories there is a Websites category with a field for typing a URL into by hand. It is not buried in Content Restrictions. It is right there in the ordinary limit sheet.

What it does not do is reach a browser that is not Safari. Chrome, Firefox, Brave, Edge and Arc do their own networking and never ask Screen Time's opinion about the page they are loading. So the limit is real, the limit is correct, and the limit is invisible to the browser you probably use for eleven hours a day. Which browsers can be held shut by anything at all, and how, is its own table.

Test yours rather than trusting this paragraph. Add one site, open your browser, type the address. Thirty seconds, and it tells you more about your own machine than any article can.

The per-site half of the report, for the same reason.

Safari reports what you did site by site, so Safari's rows in the weekly report are worth reading. Every other browser is one row with its own name on it and a number beside it. Four hours in Google Chrome is a true statement and a useless one.

Always Allowed, which is a separate list on each machine.

The apps you exempted from Downtime on the phone are phone apps. The Mac keeps its own list, and it starts out as Apple's defaults rather than yours. This one is not a gap so much as a chore, and it is the chore people discover at 9:02pm when Downtime has just swallowed the thing they were working in.

The setting on your Mac that is not about your Mac

Screen Distance is in the Screen Time pane on a Mac. You can find it, you can switch it on, and it will do absolutely nothing to your Mac, because it works by watching your face with the TrueDepth camera and your Mac does not have one. Turning it on from the Mac turns it on for the iPhone or iPad signed in to the same Apple Account. You can put your nose on the MacBook and no alert will ever appear.

Which is the clearest thing in this whole article, if you want one image to carry away. That pane is not the settings for a computer. It is the control panel for an account, drawn on whichever machine you happen to be looking at, and not every switch on it is wired to the machine in front of you.

The three gaps that decide whether any of it holds

The browser is one application and forty rooms.

Screen Time can only ever point at something the system has a name for. On a phone, the thing eating your evening has an icon, a name and a bundle identifier, and you can point straight at it. On a Mac it is a tab, inside an application that also holds your bank and your email and the document you were supposed to be writing. There is no version of "limit Chrome to ninety minutes" that you will accept twice. The four honest ways round this on a Mac today, and where each one leaks, are laid out in how to block a website on a Mac in every browser at once.

Half your rules name things that do not exist over there.

Go and look at your own App Limits list on the phone and count how many of them name an app with no Mac equivalent. For most people it is nearly all of them. That is not a sync failure. It is what happens when you take a rule written in the vocabulary of one system and hand it to a system that does not share the nouns.

On a Mac you are the administrator, and Screen Time is per account.

Every setting above lives in a System Settings pane inside your own user account. Add a second user account to the same Mac and it arrives with Screen Time off, because Screen Time is configured account by account. Nobody forgot to fill that hole. It is the reason you bought a computer instead of a bigger phone. It does mean that on a Mac the last mile cannot be a settings problem, because the person the settings are protecting you from has the password.

The whole thing on one page

What the middle column is telling you

Almost everything is there. That is the honest headline and it is better news than most articles about this will give you. The Mac really does have Screen Time, it really is the same account, and the schedule really does cross.

Now read the right-hand column and notice that every failure in it is the same failure wearing different clothes. Screen Time can name an app, and it can name a time. On a phone, that is enough, because the thing you are trying to stop is an app and it happens at a time. On a Mac, the thing you are trying to stop is a tab that has no name the system recognises, opened by somebody the system has correctly identified as the owner.

So there is a real ceiling here, and it is worth knowing where it is before you spend a Sunday afternoon on the far side of it. The settings will give you the evening. They will not give you Thursday at half past eleven, because at half past eleven the settings and the person changing them are the same person and always were.

Which is where we admit what we make. Scrappy is a small dog who stands in front of the apps you name on your iPhone. Three rules and no fourth: quiet hours, a daily limit, or a limit on how many times a day you are allowed to open the thing. He starts polite, and every knock costs him a little patience, until the fourth one, where he is down to a single word. Getting past him costs a treat, and a treat costs roughly two thousand steps of real walking. Treats are earned. They have never been for sale and they never will be, because a guard you can pay is a decoration.

He is not on your Mac. The Mac app has not shipped, and a link at the bottom of a web page is not going to change what your laptop does this evening. When it does ship it will be the same three rules and the same dog and the same treats, walked for rather than bought.

Until then, the useful order is the one you are already in. Do the phone properly, because the phone is the screen that comes to bed and the only one that is in your hand at 11:40. Then use the table above to get the clock working on the laptop, and accept that the browser stays open. A laptop is a worse place to lose an evening, which is the first piece of good news in this article. Nobody scrolls a MacBook in bed for three hours. They fall asleep on it.