Calendar alerts on Mac: set them up and fix missing ones

To set calendar alerts on a Mac, open Calendar, choose Calendar > Settings, click Alerts, pick an account and choose a default for Events, All Day Events and Birthdays. To change a single event, open it and click its alert line. If alerts still don't appear, check System Settings > Notifications > Calendar, your Focus settings, and whether that calendar is set to ignore alerts.

Each of those has details that trip people up, such as defaults that apply to only one account and invitations that arrive with no alert at all.

Set default alerts in Calendar

Default alerts are set per account, so a Mac with an iCloud calendar and a work calendar has two sets of defaults to check.

1. Open Calendar and choose Calendar > Settings (Preferences in older versions of macOS).
2. Click Alerts.
3. Choose an account from the Account menu.
4. Set Events to the warning you want for anything with a start time. For meetings, 5 or 10 minutes before suits most people.
5. Set All Day Events and Birthdays. These have their own choices, such as 9 AM on the day itself, or a day or a week before.
6. Repeat for every account in the menu.

The same pane has two more options worth knowing. Time to Leave uses your location, the event's location and traffic to tell you when to set off for a meeting in person, so give events a real address if you want it. And if you see a checkbox to use these default alerts on only this computer, turning it on keeps the Mac's defaults from following the account to your other devices, which suits people who want a different warning on their phone.

A new default applies to events you create from now on. It may not change events already on your calendar, and invitations from other people don't always pick it up, so open your next few meetings after changing it and look at their alerts.

Set an alert for one event

To change the alert on a single event, double-click the event to open it, then click its alert line, which shows the current setting or None. The menu offers:

• None and At time of event
• A set of times before the event, from 5 minutes up to a couple of days
• Custom…, for anything else

Once an event has one alert, Calendar offers a line for another, so a meeting can have a 10 minute warning and a 2 minute one. If the event repeats and you change its alert, Calendar asks whether to change only this occurrence or all of them.

Custom lets you type any number of minutes, hours or days. In most versions it also lets you change what the alert does, for example a message with a sound instead of a silent one, or an email. Use Custom for a last warning closer than 5 minutes, since the ready-made list jumps from 5 minutes straight to the start time.

Why aren't my Calendar alerts showing up on Mac?

First, test it. Make an event that starts in a few minutes, give it an alert at the time of the event, and carry on working. If nothing appears, work down this list. Most problems turn out to be one of the first four.

A few of these need more explanation.

Banners. System Settings puts it plainly: banners appear in the upper right corner and go away automatically. If you were typing or reading when one came, you never saw it. Switching Calendar to Alerts is the single most useful change on this list.

Focus. When a Focus is on and Calendar isn't among its allowed apps, its alerts can go quietly to Notification Center instead of onto the screen. Click the date and time in the menu bar to see what you missed. Focus modes on Mac explains how to choose the apps each Focus lets through.

Ignore alerts. Each calendar in the sidebar has its own Get Info window, and many have an Ignore alerts checkbox. It is easy to tick for a noisy shared calendar and forget, and then nothing on that calendar ever alerts you again.

Subscribed calendars. When you subscribe to a calendar by its web address, Calendar can strip out the alerts that came with it. That is usually what you want for a public holidays feed, and not what you want for a team schedule.

Screen sharing. System Settings > Notifications has a switch to allow notifications when mirroring or sharing the display. With it off, a meeting alert can stay hidden during the call before it. With it on, everyone watching your screen sees your notifications too, so decide which matters more to you.

A locked or sleeping Mac. A Mac that is asleep shows nothing, and an alert that fell due while it slept may only appear once it wakes. The same Notifications page has switches for showing notifications while the display is sleeping and while the screen is locked, if you want them to wait for you there.

How to get a heads up before a meeting starts

A banner in the corner is a weak signal when you are deep in work. A few ways to make Calendar's own warning stronger:

• Use two alerts. One at 10 minutes to wrap up, and one at 2 minutes, set with Custom, to actually go.
• Turn on the sound. In System Settings > Notifications > Calendar, turn on Play sound for notification. A sound reaches you when your eyes are busy.
• Keep what's next in view. In macOS Sonoma and later you can put Calendar's widget on the desktop, and it also lives in Notification Center, so the next event is a glance away.
• Snooze rather than close. When an alert appears, its Snooze option, in most versions, puts it off for a few minutes instead of dismissing it for good.

Or move the warning to where your eyes already go. Notchpals gives the top center of the screen a job: characters appear from the notch (or, on a Mac without one, from a black island in the same spot), and its Schedule characters work from your calendar. With Biscuit, Ticky, Honey or Walter in your crew and calendar access allowed, a character slides down when a meeting is between 10 and 3 minutes away.

BiscuitIt starts in a few minutes! Got everything? Sure? Check again!

Biscuit, a hamster who worries on your behalf so you don't have to, is a good match for the minutes before a call. Notchpals doesn't touch Calendar's alerts or your notification settings. It reads only when your next meeting starts, not the title, the people or the notes, and it skips events you declined, cancelled events and all-day events. It also stays quiet while your microphone or camera is in use, so a reminder that falls inside a running call doesn't get its turn. That is exactly why Calendar's own alert is still worth setting up properly. If you skipped calendar access during setup, it is in Notchpals Settings > General > Calendar.