Summary
The most reliable way to share a calendar on iPhone with colleagues who live in Google Calendar or Outlook is to connect the iCloud calendar in Keeper.sh and send busy-block copies onto the calendar they already open. If they cannot accept a write connection, Keeper.sh can also give them a times-only iCal feed. Native iPhone share does not put those hours on their calendar.
This page is for the person whose week lives on an iPhone / iCloud calendar that work colleagues on Google or Outlook cannot see — or the reverse, where the work calendar never shows on the iPhone they actually check. If both people have Apple Accounts, the calendar lives in iCloud, and full titles are acceptable, Add Person is enough and they can stop. If the real job is adding Google to the iPhone, that is /blog/how-to-add-google-calendar-to-iphone. If Apple events must exist on Google both ways, that is /blog/how-to-sync-apple-calendar-to-google-calendar.
The weakest link is that iPhone Add Person only invites iCloud users and always shows titles. Overlaying calendars on the phone is a view, not a share. A public URL still dumps full events into Other calendars.
Keeper.sh exists because it writes private copies — a placeholder title taken from the source calendar — onto the calendar colleagues already use, or a times-only feed when a copy is not possible.
iOS share, iCloud.com share, subscribe / From URL, and overlay all fail the same leftover job; the numbered Keeper.sh setup below does not.
iPhone Add Person does not share with colleagues off iCloud
An event typed on the iPhone — clinic, 1:1, school pickup — sits on iCloud. Work colleagues open Google Calendar or Outlook and that hour is free. Ticking both calendars in the iPhone Calendar app only overlays them on this phone. Add Person is missing on a Google calendar in that same list, and it will not invite a colleague who does not use iCloud. That matches the problem reported in Apple Community threads such as How to share a calendar between an Android and an iPhone? and Shared calendars — keeping an event private, where one thread states: “As far as I am aware a private event on a shared Apple calendar is not possible. Apple's logic here is that a calendar and its events is either shared or it is not.”
Apple documents the control path in Share iCloud calendars on iPhone, fetched 29 Aug 2026:
“In the Calendar app, you can share an iCloud calendar with other iCloud users.”
“You can share a calendar with one or more people in iCloud. Those you invite receive an invitation to join the calendar.”
“Tap Add Person, then enter a name or email address, or tap to browse your contacts.”
“Turn Allow Editing on or off.”
“You can also share a read-only version that anyone can view but not change.”
“Turn on Public Calendar, then tap Share Link to copy or send the URL for your calendar.”
“Anyone you send the URL to can use it to subscribe to the calendar using a compatible app, such as Calendar for macOS.”
A Google, Exchange, or On My iPhone calendar that appears in the iPhone Calendar app is not an iCloud calendar. Add Person will not be there. Apple documents no free/busy permission on Add Person.
Verdict: iPhone Add Person only invites iCloud users and always shows titles. Public Calendar removes the Apple Account requirement and still hands over the events. To remove one person, tap Delete on that person’s sheet; to stop a public link, turn off Public Calendar.
iCloud.com private share is the same Apple-Account wall
Apple: “You need to be on a tablet or computer to use Calendar on iCloud.com.” The path is calendar info in the sidebar → Sharing With (private) or Public Calendar. Source: Share a calendar on iCloud.com, fetched 29 Aug 2026.
“Allow editing: Allows the invitee to create, edit, and delete events, and track invitation responses.”
“Read-Only: Allows the invitee to view, but not edit, the calendar.”
“When you share a calendar privately, your invitees must have an Apple Account and use iCloud in order to use the calendar.”
“Only the calendar’s owner can share a private calendar.”
“When you share a calendar publicly, your invitees automatically receive an email that includes the calendar URL. An invitee doesn’t need to be an iCloud user to accept an invitation to view a shared public calendar.”
“Only the calendar’s owner can share and make changes to a public calendar.”
“Share the calendar with a link: Select Copy, then paste the link where you want to share it”
Verdict: iCloud.com private share still requires an Apple Account. Public share is a full-details URL, not a busy-only copy on theirs. Neither writes events onto a colleague’s primary Google or Outlook calendar.
Public Calendar plus subscribe or From URL is not a copy
Two controls, one leftover job. Control A is subscribing on the iPhone. Apple documents it in Add calendar subscriptions in iCloud (published May 22, 2026; fetched 29 Aug 2026) and Set up multiple calendars on iPhone:
“Subscribe to an external, read-only calendar: Tap Add Subscription Calendar, enter the URL of the .ics file you want to subscribe to (and any other required server information), then tap Find.”
iOS 26 or later:
“Tap Add Calendar, then tap Add Subscription Calendar.”
“Enter the calendar's web address, then tap Find.”
iOS 18 or earlier: same path, then tap Subscribe (not Find). Apple publishes no refresh interval. If a subscribed calendar looks stale, see /guides/subscribed-calendar-out-of-date. Keeper.sh cannot make Calendar ask sooner.
Control B is adding the public iCloud URL in Google. Source: Subscribe to someone else’s calendar, fetched 29 Aug 2026.
“To subscribe to a new calendar, you must use a computer web browser. You can't subscribe to a calendar in the Google Calendar app for Android, iPhone, or iPad.”
“You can only add a calendar with a link if the other person's calendar is public.”
“On the left, next to "Other calendars," click Add other calendars From URL.”
“The calendar displays on the left, under "Other calendars."”
Google publishes no refresh interval for From URL. A Public Calendar iCloud URL is full details. There is no busy-only toggle on Apple’s Public Calendar screen.
Verdict: Subscribe / From URL overlays a read-only public feed. It does not put a private busy copy on their primary calendar.
Overlaying calendars on the iPhone is not a share
Path: Calendar app → Calendars at the bottom → select calendars. Source: Set up multiple calendars on iPhone, fetched 29 Aug 2026.
“Select the calendars you want to view.”
Related: If you have duplicate events on your iCloud Calendar
“Select or deselect the calendar’s checkbox in the Calendar list to show or hide a calendar’s events.”
Adding Google to the iPhone (Settings → Apps → Calendar → Calendar Accounts) only brings Google in. That is the other direction; see /blog/how-to-add-google-calendar-to-iphone.
Verdict: Ticking calendars on the iPhone overlays them for the owner. It is not how you share an iPhone calendar with someone else.
Put iPhone busy blocks on their calendar with Keeper.sh
You need a Keeper.sh account. Connecting copies nothing by itself.
Two routes. Connection is the leftover job when colleagues open Google or Outlook. Feed is when they can only subscribe.
Connection (busy blocks on their calendar)
- Connect the iCloud account that holds the calendar. iCloud needs an app-specific password. Click-by-click: /docs/accounts-and-calendars.
- Connect the destination account — the Google or Outlook calendar colleagues already open, or another signed-in iCloud account if that is the leftover job. Signed-in iCloud is a valid destination. A pasted share, ICS, or subscribe link is not.
- Open the source calendar. Under Send Events to Calendars, tick the destination. One tick is one mapping. /docs/sending-events-to-another-calendar.
- Leave the privacy defaults. Copies use a placeholder title from the source calendar; description and location stay hidden. Those toggles are Pro. /docs/what-a-copied-event-shows.
- Confirm on the destination: a real event, named after the source calendar, no notes, no location, no guest list.
Busy-block copies both ways is two mappings (A→B and B→A), same as Google and Outlook. One signed-in iCloud account is enough — not two Apple IDs. That is busy-block copies, not two-way event sync, and it does not write back into meetings they organize on Apple.
Apple documents app-specific passwords in Sign in to apps with your Apple Account using app-specific passwords:
“App-specific passwords allow you to sign in to your Apple Account in apps made by developers other than Apple.”
“To generate and use app-specific passwords, your Apple Account must be protected with two-factor authentication.”
Path: account.apple.com → Sign-In and Security → App-Specific Passwords → Generate an app-specific password. Keeper.sh /docs/accounts-and-calendars notes: “iCloud and Fastmail — an app-specific password, made in their settings.”
Feed (hand a times-only link)
Use when you cannot write into their account. Recipe: /recipes/share-when-you-are-busy. Settings: /docs/shareable-calendar-links.
- Connect the iCloud account.
- Open the iCal feed. Under Calendars, tick only the calendars whose time should count as busy.
- Leave Feed Settings alone. Include Event Name / Description / Location stay off. Events read Busy. Check the disclosure line under the link — it should say the link shares event times only. Feed settings are Pro; on Free the defaults hold.
- Send the link.
- They subscribe with Apple’s Add Subscription Calendar or Google From URL. Tell them the refresh belongs to their app. Keeper.sh cannot force it.
Treat the link like a password. The default feed cannot be deleted or reissued. If it spreads, untick every calendar under Calendars.
Cadence and price
- Sources are read every minute on every plan.
- Free destinations write every 30 minutes.
- Pro writes every minute. On Pro, a change you make in Google or Outlook shows up on the other calendar the moment you make it. iCloud stays on the timer — Apple publishes no way for a calendar tool to be told an event changed. (/docs/plans-and-limits)
- Free: 2 accounts, 3 connections, 1 shareable link, 25 MCP/API calls a day.
- Pro: $5/month or $45/year.
- Guest lists are never copied, on any plan.
Why a copy (or a times-only link) instead of Add Person
- Add Person required an Apple Account and showed every title → a Keeper.sh connection writes a private copy onto the calendar colleagues already open.
- Public Calendar + subscribe / From URL was a full-details side calendar → the feed defaults to times only, events titled Busy.
- Overlay only stacked calendars on this iPhone → copies exist as real events on the destination.