Import Busy Times from Outlook.com or Microsoft 365

Zimun can read the busy times from your Outlook calendar and block your availability to match. You publish the calendar once and paste its ICS link into Zimun; Zimun refreshes it every 15 minutes and imports only the times of your events — never titles, descriptions, or attendees. From then on, a meeting in your Outlook calendar closes the overlapping Zimun slots the same way a Zimun appointment would. Customers simply see fewer available slots; nobody sees why.

This covers one direction: outside events blocking Zimun. For the other direction — seeing your Zimun appointments inside Outlook — subscribe to your Zimun calendar feed from Settings → Calendar feed. The two links together give you two-way visibility without connecting any accounts.

1. Publish your calendar and copy the ICS link

1. Open Outlook on the web and sign in.
2. Open Settings, then Calendar.
3. Choose "Shared calendars".
4. Under "Publish a calendar", select the calendar you want Zimun to read and pick a permission level. Whichever level you choose, Zimun keeps only the times of your events.
5. Click Publish.
6. Outlook shows the published links. Copy the ICS one — a URL that starts with https://outlook.office365.com/owa/calendar/ and ends in calendar.ics.

2. Paste the link into Zimun

1. In Zimun, open Settings → Team and open your own record. The External calendar tab appears only on your own record — nobody can paste a link on your behalf, and you cannot paste one for a teammate.
2. On the External calendar tab, paste the link into the calendar address field and save.
3. Zimun fetches the feed once, right away, and answers with "Events found in the next 14 days: N."

That message is your confirmation: the link works and Zimun could read the calendar. The number counts events in the 14-day window Zimun watches — a count of 0 is not an error if your next two weeks happen to be empty. If the check fails instead, the message states the problem and nothing is saved; fix the link and try again.

Once connected, the tab shows the link masked, a "Last refreshed" timestamp, and a Remove button. Remove stops the import and deletes every busy block the feed created.

3. How fresh the import is — an honest caveat

Zimun refreshes the feed every 15 minutes; "Last refreshed" on the External calendar tab shows the most recent run. But with Outlook there is a second delay you should know about, and it is on Microsoft's side: Microsoft regenerates published calendar files with a delay, so a change in your calendar typically takes a few hours to appear in the published file. Zimun's 15-minute refresh comes on top of that. Plan for it: a meeting you accepted this morning will reliably block your Zimun slots, but a meeting added minutes ago may not block them yet. If a new commitment must close a slot immediately, do not rely on the published feed to carry it in time.

4. Keep the link private

The ICS address of your calendar grants full read access to that calendar to anyone who holds it — treat it like a password. Zimun stores the address encrypted, shows it only in masked form, and keeps only busy times from your calendar: the start and end of busy slots, never titles, descriptions, or attendees. Event contents pass through Zimun's server only transiently during each refresh and are never stored. Removing the feed deletes the address and every imported busy slot.

Connecting a calendar is always each member's own voluntary step: whether and how an organization asks its staff to do so — including any works-council involvement or other employment-law obligations — is the organization's responsibility as employer, not Zimun's.

Do not post the link, and do not send it to anyone you would not hand your calendar to. If you think the link has leaked, unpublish the calendar on the same "Shared calendars" screen (the old link stops working), publish it again, and paste the new link into Zimun.

5. Troubleshooting

• The External calendar tab shows a needs-attention state: the feed has stopped answering. The usual cause is that the calendar was unpublished in Outlook. Publish it again (section 1) and paste the new link into Zimun. The state appears only after a couple of hours of failed refresh attempts, so a single network hiccup will not trigger it.
• A recent change is not blocking your slots yet: see section 3 — Microsoft's published file lags your calendar by up to a few hours. Check again later before assuming the feed is broken.
• An event is not blocking your slots at all: events marked free are skipped on purpose — only busy time blocks availability. Also check the horizon: Zimun watches the next 14 days, so events further out start blocking as they roll into that window.
• Slots disappeared unexpectedly: that is the feature working. All-day events block the whole day, and tentative events count as busy. Move or delete the event in Outlook, or remove the feed in Zimun to stop the import entirely.
• The validation check keeps failing: make sure you copied the ICS link, not the HTML one, and that the copy is complete — the URL is long, and a truncated copy will not fetch.