How a reminder reaches you
A push on your iPhone, a banner on your Mac, and a row in Updates.
A reminder is a task's bell. At the moment you chose, your iPhone gets a push, your Mac app shows a banner, and a row reading Reminder lands under the task's title in Updates. A due date on its own never interrupts you. The reminder is the one thing in Roma that does, and only for a moment still ahead.
What a reminder needs
A due date. A reminder without one would be a task that buzzes you and shows in no list. A due date is a day: a task due Friday reads Fri, sorts with Friday's tasks and stays silent. A reminder adds the moment. Due dates, times and reminders covers the due date itself.
A reminder gets set in one of four ways:
Type or say a time. "Friday at 5 pm" sets the time and arms the reminder in one go. Words have fixed hours: morning is 7:00, noon 12:00, afternoon 2:00 PM, evening 6:00 PM, tonight 8:00 PM, midnight 0:00. "In an hour" is now plus an hour, rounded up to the next five minutes. A bare "7pm" means today, or tomorrow once that moment has passed.
The date picker. Two rows sit under the calendar on every task, dated or not: Set a time, and Remind me with a checkmark. Set a time starts from your Reminder time, and Remind me arms the bell. Each commits at once. On a task with no date the day becomes today, and the calendar shows it.
The task's menu. Remind me, with a checkmark while it is on, once the task has a due date. On the Mac and in the browser the right-click menu has it too.
The operator. "Remind me about the dentist tomorrow at 9" in any chat.
The chip on the task says what will happen: a bell when the reminder is armed, a clock when the task has a time but the bell is off, a calendar when it is a day and nothing more. Beside the bell is the hour the phone will ring: "Tomorrow 7 AM", or on the day itself the hour alone, "5 PM".
A task with a date and no time fires at your Reminder time, 7:00 AM unless you changed it in Settings → Notifications. A moment that has already passed arms no bell: "at 5 pm" said at 5:10 is due today at 5 and reads as overdue, and nothing rings. Remind me on an overdue task rolls the bell forward to the next time that hour comes around, today if it is still ahead, otherwise tomorrow, and the due date stays as it was.
What arrives, on each device
On your iPhone, a push at the moment, titled with the task and carrying the reminder's own moment on its second line, "Today at 7:00 PM". A tap opens the task. There is no Complete or Snooze on it. With Roma open in front of you it shows as a banner too.
On your Mac, the Mac app shows a banner at the moment and a click opens the task. The Mac app schedules reminders itself, from the tasks it has synced, so a reminder fires only while the app is running. Launch at login, in the app's Settings, is what keeps it running. Anything missed in the last six hours shows when the app comes back.
In the browser, there is no push. The row in Updates and the dot on the bell are what you see.
In Updates, on every client, a row reads Reminder under the task's title. It is the record, and it never pushes a second time. Updates explains the bell.
Every device you have registered gets the push, or none does: the Reminders switch in Settings → Notifications is your account's, not a device's. Turned off, it stops the push and nothing else. The app icon's badge wears its one mark until you have read what the reminder is about.
The permission your phone asks for
The iPhone asks for permission the first time you set a reminder, never at launch. The reminder is armed either way, and if you declined, Settings → Notifications shows an Enable notifications row that takes you to the phone's setting. The Mac asks Notification Center on its first banner. Setting more reminders never asks again.
When a task moves
Move the due date or the time and the reminder moves with it, and fires again at the new moment even if the old one already rang. Move the moment into the past, "it was due this morning", and the bell goes quiet: the task is overdue, not due later. Complete the task, or delete it, and nothing rings. A reminder that could not go out within six hours of its moment is dropped rather than arriving late.
On a task someone shared with you, the reminder you set is yours alone and rings on your devices.
Questions people ask
Why did my task not remind me?
Check four things. The task has a due date and its chip wears the bell, not the calendar or the clock. The Reminders switch in Settings → Notifications is on. On the iPhone, notifications for Roma are allowed in the phone's settings. On the Mac, the Mac app was running at the moment, since it schedules reminders itself, and the browser shows no push at all.
Can I be reminded about a task that has no time?
Yes. Turn on Remind me for a task with a date and it rings at your Reminder time that day, 7:00 AM unless you changed it in Settings → Notifications. The task keeps its date and gets no time of its own.
Can a task have a time without reminding me?
Yes. Set the time and leave Remind me off. The chip shows the clock and the hour, the task sorts by that hour inside its day, and nothing rings. Turn Remind me on later and it rings at that hour.