How to Share an Outlook Calendar

Summary

If they only need the other person to accept Share calendar and look or edit inside Outlook, Microsoft’s share is enough and they can stop. If those hours must exist as busy blocks on a calendar the other person already uses — without dumping titles, without a published calendar, including outside the org — connect the Outlook calendar in Keeper.sh and send busy-block copies. Native share and overlay stay read-only for that leftover.

This is for anyone who needs another person — a partner, teammate, or client — to see an Outlook calendar. If Google is the calendar being shared, see /blog/how-to-share-google-calendar; if iPhone / iCloud is the calendar being shared, see /blog/how-to-share-iphone-calendar; to overlay a Google calendar inside Outlook, see /blog/add-google-calendar-to-outlook; to put Google hours onto Outlook as busy blocks, see /blog/sync-google-calendar-with-outlook.

Share calendar puts a second calendar under People's calendars. Can view when I'm busy greys titles on that shared calendar; it does not write events onto the recipient’s own calendar, so Find a time on them still looks empty. Can view titles and locations dumps titles and locations — there is no titles-without-details rung. A published ICS or Upload from file is public, pull-only, or a snapshot, not a private busy copy, and outside the org Microsoft’s share becomes an ICS URL on the recipient’s clock.

Keeper.sh writes private copies — a placeholder title from the source calendar — onto the calendar they already open. Signed-in iCloud is a valid destination. Two mappings if both ways. Connecting copies nothing by itself.

The rest shows how Share calendar works, why each built-in level fails the leftover, and the numbered Keeper.sh setup.

Outlook’s Share calendar is how to share an Outlook calendar when the other person only needs to look at, or edit, this calendar in Outlook.

In new Outlook, Microsoft lists these steps (Share an Outlook calendar as view-only with others, fetched 30 Aug 2026):

From the navigation pane, select Calendar.
On the Home tab, select Share calendar, and if you have more than one calendar, select which calendar you want to share.
Type the person in Enter an email address or contact name.
Use the drop-down next to their name, then click Share.

In Outlook on the web the labels are the same (Share your calendar in Outlook on the web, fetched 30 Aug 2026):

At the bottom of the page, go to Calendar.
On the toolbar at the top, select Share, and choose the calendar.
Enter the name or email address.
Choose how they can use the calendar, then click Share.

Microsoft says the recipient must accept before it shows up: “The person you're sharing a calendar with will receive an email invitation to share their calendar. Once they accept, they can add your calendar to their own view.”

The permission drop-down currently shows these levels:

Can view when I'm busy — “Select Can view when I'm busy to give them permission to see only when you are busy, but not the details of items on your calendar.”
Can view titles and locations — “Select Can view titles and locations to give them permission to see when you're busy, plus the titles and locations of items on your calendar.”
Can view all details — “Select Can view all details to give them permission to see all details of items on your calendar. This option allows others to view your calendar but not make changes to it.”

Those busy / titles-and-locations rungs are on the view-only and Outlook on the web pages. Outlook.com’s share page lists only Can view all details and Can edit.

Outlook on the web gives the same labels a shorter gloss: “Can view when I'm busy lets them see when you're busy but doesn't include details like the event location.” “Can view titles and locations lets them see when you're busy, as well as the title and location of events.” “Can view all details lets them see all the details of your events.” “Can edit lets them edit your calendar.” “Delegate lets them edit your calendar and share it with others.”

If edit or delegate is the job, Microsoft covers that separately in Share and access a calendar with edit or delegate permissions in Outlook. Microsoft’s older “Reviewer / Editor / Delegate” labels now map to the simplified dropdown (Calendar sharing in Microsoft 365, fetched 30 Aug 2026): Free/Busy time → Can view when I'm busy; Free/Busy time, subject, location → Can view titles and locations; Reviewer / Full details → Can view all details; Editor → Can edit; Delegate → Delegate.

A few honest details from Microsoft’s docs:

The invitation is not access until they accept.
Levels are per person, not one level for the whole calendar.
There is no rung that shows titles and withholds locations.
Private events: “Calendar items marked private are protected. Most people you share your calendar with see only the time of items marked private, not the title, location, or other details.”
Sharing with Gmail: “When sharing your calendar with someone who's not using Outlook on the web, for example, someone using Gmail, they'll only be able to accept the invitation using a Microsoft 365 or an Outlook.com account.”
An ICS generated for an outsider is read-only: “ICS calendars are read-only, so even if you grant edit access to other people, they won't be able to edit your calendar.” “How often your ICS calendar syncs depends on the email provider of the person you've shared it with.”

Same-tenant shares can sync instantly. Cross-tenant or consumer recipients cannot. Microsoft says: “Instant syncing is enabled only if both users are in the same Microsoft 365 tenant, or if the calendar is shared by an Outlook.com user.” And: “If the recipient is in Outlook.com, the calendar will update approximately every three hours. If the recipient is in Gmail.com, the calendar might be updated every 24-48 hours.”

Lock-down My organization. If colleagues can already see the week and nobody was added by hand, that is My organization / tenant Default, not a missing Share button. Outlook on the web notes: “You might also see an entry for My organization in the list of people with whom you’ve shared the calendar. This is the default level of detail that others in your organization, or federated organizations, can see when viewing your calendar in Scheduling Assistant.” A Microsoft Q&A thread still live on 30 Aug 2026 shows the same problem: one user said, “i’m trying to get my calendar blocked and right now everyone in the organization can view it,” and then, “When I click on my org, it still has add or remove greyed out” (Permissions on Outlook Calendars, asked 3 Feb 2025). That greyed-out row is an admin policy. Ask whoever runs the tenant.

To change or remove an individual share, Outlook on the web says: under Calendars, right-click the calendar → Sharing and permissions, find the person, choose a new level, or remove them. “Choose the person you want to stop sharing your calendar with and select. The person is now removed from the list of people who have access to your calendar. Their copy of your calendar will no longer sync to your calendar or receive updates.” To hide a single event instead, mark it Private; recipients see the time, not the title, location, or other details.

Verdict: Share calendar is the official path when the other person only needs to look at, or edit, this calendar in Outlook. Sharing and permissions is how you lower a person or remove them; My organization is why a colleague can already see the week. If that was the whole job, stop.

Can view when I'm busy is a side calendar, not a copy on theirs

Here is the concrete problem. They share an Outlook calendar at Can view when I'm busy. On their side, grey blocks appear under People's calendars — a second calendar they can turn on or off. Their own calendar for that hour is still empty. A colleague running Find a time or Scheduling Assistant on them sees none of those blocks. Switching the share to Can view titles and locations would hand over titles and locations on the shared calendar, but still would not write a copy onto theirs. Outside the org, Microsoft’s share becomes an ICS URL; it still does not write a private busy copy onto the calendar they already use.

Microsoft confirms the result on the same view-only page (Share an Outlook calendar as view-only with others, fetched 30 Aug 2026): “You can add any team member's calendar and see their default calendar sharing details (for most organizations, usually free/busy sharing).” And: “View shared calendars under People's calendars.” In new Outlook that is Show all → People's calendars. That is still a second calendar in Outlook.

Verdict: Can view when I'm busy hides titles on a side calendar. It does not put a busy copy on theirs.

Can view titles and locations dumps titles

The control is Can view titles and locations. Microsoft defines it as “see when you're busy, plus the titles and locations of items on your calendar.” The next rung is Can view all details, which shows everything.

There is no titles-without-details rung, so the dropdown cannot share an Outlook calendar without details. Raising the rung hands over titles and locations on the shared calendar, and it still does not write a copy onto the recipient’s own calendar.

Verdict: Can view titles and locations is a fixed bundle. It cannot hide the location and keep the title, and it is still not a copy on theirs.

Publish, ICS, and Upload from file are not a private busy copy

Three controls, one leftover job. These also cover the outside-the-org case: when Microsoft’s share goes to Gmail or another third-party service, it generates an ICS URL, and the refresh belongs to the recipient’s app.

Publish a calendar (HTML / ICS link). In the new Outlook, the path is View tab → Calendar settings → Calendar → Shared calendars → Publish a calendar (Share an Outlook calendar as view-only with others, fetched 30 Aug 2026). Microsoft says: “If you choose an ICS link, recipients can download the ICS file and import it into Outlook. This will add your events into their calendar, but recipients won't automatically receive any updates to your calendar.” “Alternatively, recipients can use the ICS link to subscribe to your calendar through Outlook. They'll see your calendar alongside their own and will automatically receive any updates to your calendar.” “HTML and ICS calendars are read-only, so recipients won't be able to edit your calendar.” “How often your ICS calendar syncs depends on the recipient's email provider.”

For cross-tenant or external recipients, Calendar sharing in Microsoft 365 (fetched 30 Aug 2026) confirms: “This configuration currently generates an Internet Calendar Subscription (ICS) URL. The shared calendar recipient adds the shared calendar using the ICS URL, and the sync timing is determined by the recipient's calendar service.” “If the recipient is in Outlook.com, the calendar will update approximately every three hours. If the recipient is in Gmail.com, the calendar might be updated every 24-48 hours.” Cross-tenant with external sharing enabled syncs approximately every three hours. Instant sync stays same-tenant.

Upload from file. In Outlook on the web, this is Add calendar → Upload from file (Import or subscribe to a calendar in Outlook.com or Outlook on the web, fetched 30 Aug 2026). “When you import an .ics file, your calendar doesn't refresh the imported events, even if the calendar's owner makes an update.” “When you import an .ics file, you get a snapshot of the events in the calendar at the time of import. Your calendar doesn't refresh the imported events automatically -- even if the calendar's owner makes an update.”

Subscribe from web. Same article: Add calendar → Subscribe from web. “When you subscribe to a calendar, your calendar will automatically refresh if the other calendar is updated. This can sometimes take more than 24 hours.” “This update can take more than 24 hours, although updates should happen approximately every 3 hours.” That is a subscription on Microsoft’s clock, not a copy they control. If the real job is overlaying or subscribing a Google calendar inside Outlook, see /blog/add-google-calendar-to-outlook.

A pasted ICS, subscribe, or published calendar is pull-only in Keeper.sh, never a destination.

Verdict: Publish a calendar or an ICS link is a public or pull-only feed. Upload from file copies once. Neither writes a private busy copy onto theirs.

Put busy-block copies on their calendar with Keeper.sh

You need a Keeper.sh account. Connecting copies nothing by itself. As /docs/accounts-and-calendars puts it: “Connecting copies nothing by itself. Events only move once you send them to another calendar.”

The source is the Outlook calendar being shared. The destination is the calendar the other person already uses — their Google, Outlook, or signed-in iCloud. A pasted share, ICS, subscribe, or published calendar is not a destination. Overlay and named share stay native. Keeper.sh is for when they need a write copy that shows the other person busy without dumping titles.

If the destination is iCloud, Apple requires an app-specific password (Sign in to apps with your Apple Account using app-specific passwords, Published Date October 08, 2025; fetched 30 Aug 2026): “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.” “Sign in to your Apple Account on account.apple.com.” “In the Sign-In and Security section, select App-Specific Passwords.” “Select Generate an app-specific password, then follow the steps on your screen.” “Enter or paste the app-specific password into the password field of the app when signing in to your Apple Account.” Keeper.sh’s docs add: “iCloud and Fastmail — an app-specific password, made in their settings.”

Connection (busy blocks on their calendar)

Sign in to Keeper.sh and connect the Microsoft / Outlook account that holds the calendar on Microsoft’s permission screen. Work or school: Connect Microsoft 365. Personal Outlook / Hotmail / Live: Connect Outlook. The click-by-click is in /docs/accounts-and-calendars. “Google, Outlook and Microsoft — sign in on their own permission screen and grant calendar access. Keeper.sh never sees your password.”
Connect the destination — the calendar the other person already uses. If that destination is iCloud, generate an app-specific password and paste it into Connect Apple Calendar. Signed-in iCloud is a valid destination. A pasted share / ICS / 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 says: “Each calendar you tick becomes one connection. Events are copied into it, one way, and the copies are kept corrected as the originals change.”
If they need the other direction too, open the other calendar’s page and tick back. That is two mappings (A→B and B→A), the same as Google and Outlook. One Apple ID — not two Apple IDs. Free is 2 accounts and 3 connections, so a pair plus one extra still fits.
Leave the privacy defaults on. Copies use a placeholder title from the source calendar; description and location stay hidden. Those toggles are Pro. Guest lists are never copied. /docs/what-a-copied-event-shows says: “A copied event shows the name of the calendar it came from in place of the real title, and no description or location. That is the default on every plan.”
Confirm on the destination: a real event, named after the source calendar, no notes, no location, no guest list. Wait for the next write. Google and Outlook on Pro can land within seconds because they notify Keeper.sh. Keeper.sh does not notify them. iCloud stays on the timer on both plans.

If nothing arrives, see /guides/event-has-not-arrived. If the same event appears twice, see /guides/same-event-appears-twice. /docs/sending-events-to-another-calendar: “Untick the calendar in Send Events to Calendars and new events stop being copied. Events already copied stay where they are.” If they connected a URL instead of signing in, they can send from it, not into it. Keeper.sh does not take an uploaded .ics as a live connection.

Feed (hand a times-only link)

Use this when they cannot write into the other person’s account. The recipe is /recipes/share-when-you-are-busy. /docs/shareable-calendar-links notes: “Unlike sending events to another calendar, a link copies nothing into anyone's calendar.”

Connect the Outlook / Microsoft 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, and 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. Treat it like a password. The default feed cannot be deleted or reissued. If it spreads, untick every calendar under Calendars.
They subscribe with Outlook Add calendar → Subscribe from web or Google From URL. Overlay / subscribe Google into Outlook is /blog/add-google-calendar-to-outlook if that is the job. Tell them the refresh belongs to their app: Microsoft says Outlook.com subscribe updates approximately every three hours and can take more than 24 hours. Keeper.sh cannot force it. If it looks stale, see /guides/subscribed-calendar-out-of-date.

Cadence and price

From /docs/plans-and-limits:

Sources are read every minute on every plan.
Free destinations write every 30 minutes.
Pro writes every minute, and Google and Outlook notify Keeper.sh so a copy can land within seconds. “On Pro, Google Calendar and Outlook notify Keeper.sh the moment an event changes, so the copy lands within seconds.” Keeper.sh does not notify them.
“iCloud, Fastmail and other CalDAV calendars are checked on a timer on either plan, because Apple publishes no way for a calendar tool to be told an event changed.”
Free: 2 accounts, 3 connections, 1 shareable link, 25 MCP/API calls a day.
“Pro is $5 a month, or $45 a year paid annually.”
Guest lists are never copied, on any plan.

Can view when I'm busy left grey blocks on a side calendar; Find a time on the recipient still looked empty — a Keeper.sh connection writes a private copy onto the calendar they already use.

Can view titles and locations dumped titles and locations, and there is no without-details rung — copies stay private by default (placeholder title, description and location hidden). The feed, when subscribe is the only option, defaults to times only with events titled Busy.

Publish a calendar, an ICS link, or Upload from file was public, pull-only, or a snapshot, and outside the org Microsoft’s share is an ICS URL — copies exist as real events on the destination and stay updated. Native share remains the right path for look or edit.