Calendar RelayFor Mac and iPhone
Calendar copies with a receipt.
Copy only the events you choose into the calendar others see. See the plan before the first run and any big change. Undo recent runs if you change your mind.
Coming soon to the App StoreOne purchase covers your Mac and your iPhone.
Work shifts in the family calendar
Just the shifts, kept up to date as the rota changes.
Busy, without saying why
Colleagues see the time is taken, not what for.
Several calendars in one
An event in two calendars is copied once.
Preview
See it first
- The first run, and every run you start in the app, opens with a preview: what will be added, changed and removed.
- After that, a watched copy updates itself. On the Mac, whenever a calendar changes. On the iPhone, when you open the app, when iOS allows a background check, or from a Shortcut on a schedule.
- A run that would change more than you allow waits for you.
Activity
Undo it later
- Activity lists each device's latest runs, fifty unless you choose another number, and what each changed, field by field.
- Undo any of them. Added events go, changed ones go back, removed ones return. If the app can't do that safely, it tells you why.
- Turn on Share with My Devices and your Mac and iPhone keep the same watched copies and history in your own iCloud. A watched copy's run can usually be undone from either.
Its own copies
Your events stay yours
- Your own events are never modified or deleted. The app changes only the copies it made, and each copy says so in its notes.
- A copy is never taken for a source, so nothing is copied twice.
Filters and blockers
You decide what leaves a calendar
- Copy only events with a certain word in the title, or leave out those with another.
- Leave out declined or unanswered invitations, cancelled events, all-day events, or events marked tentative or free.
- Blockers show only that the time is taken: your title, marked busy, none of the details.
- Choose whether location, notes and web address come along.
- Write
#nocopyin an event's notes and it stays put. - An event in several calendars is copied once, with the details from each.
Works with the calendars you already have
Any calendar your Mac or iPhone shows: iCloud, Google, Microsoft Exchange, CalDAV or a subscription. No extra sign-in.
A calendar only your iPhone can see is copied by your iPhone.
From Shortcuts, too
Run watched copies from Shortcuts, on a schedule or a trigger. They run like any automatic run, with no preview and the same limits.
Private by design
No account, no analytics, no ads and no server of ours. The app talks only to iCloud: yours for your data, and the app's own storage for a report you choose to send. A report carries no name unless you add one.
One purchase covers your Mac and your iPhone.
Coming soon to the App StoreFor macOS 14 and iOS 17, or later. The calendars in the pictures are invented.
Common questions
Which calendars can it use?
Any calendar in the Calendar app on your Mac or iPhone: iCloud, Exchange, Google, CalDAV or a subscription. The destination must be a calendar you can edit. For Exchange on the Mac, see below.
What is a watched copy?
A copy the app keeps up to date. New events in the source are added, changes are carried over, and removed events leave the destination too. You make the first run, from a preview. After that it runs on its own: on the Mac whenever a calendar changes, on the iPhone when you open the app, when iOS allows a check, or from a Shortcut. A run that would change more than you allow waits for you.
Why did it not change an event I expected it to?
Calendar Relay only changes events it made. Every copy carries the line Copied by Calendar Relay in its notes, with a short random reference that says nothing about the event. If an event in the destination matches one in the source but came from you or another app, it is left alone and shown as unchanged. To hand it to the app, delete it and run the copy again. A copy you duplicate in Calendar keeps the app's line and reference, so it still counts as the app's copy. A copy you delete is not made again. It appears under Deleted Copies in Activity, where Copy Again brings it back. If a calendar suddenly reads empty, or loses more than three copies and at least half of them at once, the app takes that for the calendar reloading and makes them again.
Can I undo a run?
Yes. Activity lists the recent runs with what each changed, field by field: the latest fifty on each device, or as many as you choose in Settings. Undo removes what was added, puts back what changed and restores what was removed. Anything the app can't identify for certain is left alone.
How do I keep one event from being copied?
Write #nocopy in its notes and no watched copy will copy it. An existing copy is removed at the next run. You can change the tag in Settings.
Can my Mac and iPhone share the same watched copies?
Yes. Turn on Share with My Devices and your watched copies and history are kept in your own iCloud, with each device showing the other's runs. A watched copy's run can usually be undone from either device, and the app says when it can't. One device at a time copies each calendar, and the app shows which.
What does a copy carry, and what is kept up to date?
The event's title and times and, if you allow them, its location, notes and web address. A blocker carries only its time and your title. Each occurrence of a repeating event becomes its own copy. When the source changes, the copy follows. Busy or free is taken from the source when the copy is made and stays that way, and a blocker is always busy. Events with the same title and time in two of a watched copy's calendars count as one and are copied once. A switch in its settings turns that off.
My Mac no longer shows my work Exchange calendar. Can Calendar Relay still copy it?
Microsoft is retiring the way macOS reads Exchange Online calendars (Exchange Web Services, blocked in stages from October 2026 and switched off on 1 April 2027). Apple has said a later macOS update will read them another way. Until then you have two options. On the Mac, publish the calendar from Outlook on the web with its details, subscribe to it in Calendar, and put the subscription in the Exchange calendar's place in the watched copy. The preview should show nothing to add or remove, and the copies carry on. Or make the watched copy on your iPhone, which reads Exchange another way and is not affected, as long as your organisation lets the phone's Calendar app show the calendar. The iPhone does not take over copies the Mac made. It leaves them as they are, so undo the Mac's runs in Activity before the iPhone's copy makes its own.
Support
The quickest way is the app. On the Mac, the Help menu has Report a Problem…, Suggest a Feature…, Roadmap and Write to Us by Mail…. On the iPhone, the first three are in Settings once the app has access to your calendars. Before that, Write to Us by Mail is on the first screen. You see the whole report, with everything the app adds, before you press Send.
Reports carry no name, so we can't answer them. For an answer, write to support@calendarrelay.app, or use Write to Us by Mail in the same places. Please mention your system version and what you expected to happen.
Feature requests
Tell us what you were trying to arrange and what got in the way. The Roadmap in the app shows what is being built and what is planned.
Privacy policy
Calendar Relay collects nothing about you on its own. It has no analytics, no crash reporting, no advertising and no account of ours. It talks only to iCloud, through Apple's framework: your own iCloud for your data, and the app's own iCloud storage for a report you send. There is no server of ours. The one thing that ever reaches us is a report or a request you write and press Send on.
Who is responsible
Calendar Relay is made and sold by Cornelius Hempel, who is the “we” of this policy and answers for the data it describes. Write to support@calendarrelay.app, or by post to Cornelius Hempel, Postfach, 8032 Zürich, Switzerland.
Calendar access
The app asks the system for permission to your calendars, which you grant or refuse in the standard prompt and can change at any time under Privacy & Security ▸ Calendars in Settings. That access is used only to read the calendars you choose and to write copies into the destination you choose. Calendar contents are never sent to us. The one exception is calendar and event names in a problem report, and only if you switch that on for that report.
What is kept on your devices
Inside the app's own container, Calendar Relay keeps your settings, a history of its runs, which is what makes undo possible, and a record of the events it created, so it can tell its own copies apart from yours. On the iPhone, all of it is removed when you delete the app. On the Mac, macOS keeps an app's data after the app is deleted: it stays in the folder Finder shows as Calendar Relay in ~/Library/Containers, until you delete that folder. Deleting the app does not remove the copies it made: they stay in your calendars, and once its record is gone, the app no longer updates or removes them, even if you install it again. If you want them gone, undo the runs that made them in Activity before you delete the app, or delete them in Calendar once the app is gone. You choose how much detail a copy carries: location, notes and web address can each be left out, and a blocker carries none of the original's details, only its time, the title you choose, and a line saying Calendar Relay made it.
Your own iCloud
If you turn on Share with My Devices, the watched copies, the record of copies and the history are stored in the private database of your iCloud account, so your Mac and your iPhone see the same. Of the history, iCloud keeps the newest runs of each device, as many as Activity keeps. Older ones are removed from it. Only your account can read it. We cannot. With Advanced Data Protection turned on, it is end-to-end encrypted. Deleting the app or stopping sharing leaves it there. To remove it, open your name ▸ iCloud in Settings (System Settings on the Mac), then the list of what uses your storage, and delete Calendar Relay's data. Your devices then stop sharing. None of this removes the copies the app made: they stay in your calendars.
Reports and requests you send
A report or a request goes only when you press Send, and carries what the screen showed you: your words, the app and system versions, and for a problem report a summary of the app's state (counts and settings, never a calendar or event name). Names are included only if you switch on Include calendar and event names for that one report, and then as they appear in the app, except that email addresses and web links in them are replaced before you see the report: a calendar named after a person still sends that name. Beyond that, the app adds no name, email address or device name.
It travels through the public part of the app's iCloud storage, which only we can read and which Advanced Data Protection does not cover. iCloud stamps it with a number for your account, which we cannot turn into you. We never read it, and when we take the report in we delete it from iCloud and check that it is gone. We keep what you wrote only as long as it takes to deal with it, twelve months at most, and never share it.
Reading the roadmap needs no account and sends nothing about you to us. If you write to us by mail instead, we see your address and use it only to answer you.
To have a report or your mail deleted, write to support@calendarrelay.app and we will delete it. For a report, give its title and the day you sent it: we cannot tell who sent a report, so those are the only way we can find yours.
Third parties
None, apart from Apple, whose iCloud carries the app's storage. No advertising, no tracking, and no software development kits that phone home.
Changes
If this policy ever changes, the revised version will be published on this page with a new date below.