Zimun can read the busy times from your iCloud calendar and block your availability to match. You share the calendar as a public calendar once and paste its 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, an appointment in your Apple 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 Apple Calendar — subscribe to your Zimun calendar feed from Settings → Calendar feed. The two links together give you two-way visibility without connecting any accounts.
1. Get your calendar's public link
- Open Calendar on your iPhone, on your Mac, or at iCloud.com — the sharing settings are the same calendar in all three places.
- Open the sharing settings for the calendar you want Zimun to read.
- Turn on "Public Calendar".
- Choose Copy Link. The link starts with webcal://.
Paste the webcal:// link into Zimun exactly as copied — no need to change it to https; Zimun accepts it as-is.
Be aware what "Public Calendar" means before you turn it on: anyone who holds the link can read that calendar, with full event details. If the calendar contains things you would not want readable by link, consider keeping your blocking events in a calendar you are comfortable sharing this way.
2. Paste the link into Zimun
- 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.
- On the External calendar tab, paste the webcal:// link into the calendar address field and save.
- 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
Zimun refreshes the feed every 15 minutes; "Last refreshed" on the External calendar tab shows the most recent run. iCloud serves current data on its public links, so in practice a new event in your Apple Calendar blocks your Zimun availability within about a quarter of an hour.
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, turn "Public Calendar" off in the sharing settings of that calendar — the old link stops working. When you turn it back on, copy the link shown (do not assume it is the same one) and paste it into Zimun again.
5. Troubleshooting
- The External calendar tab shows a needs-attention state: the feed has stopped answering. The usual cause is that "Public Calendar" was turned off. Turn it on again, copy the link, and paste it into Zimun (section 1). The state appears only after a couple of hours of failed refresh attempts, so a single network hiccup will not trigger it.
- An event is not blocking your slots: 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 Apple Calendar, or remove the feed in Zimun to stop the import entirely.
- The validation check keeps failing: make sure you copied the complete webcal:// link, and that "Public Calendar" is still on for that calendar.