TUTORIAL

Add a calendar with a secret ICS address

Posted: June 10, 2026 · 3 min read

What a secret ICS address is

Most calendar services can hand you a private URL that contains your full event feed in iCal format. Paste that URL into manyCalendars once and your events show up in your unified view, then refresh automatically in the background. No tab needs to stay open.

The fetch happens locally, in your browser. manyCalendars does not see your URL or your events, and your calendars are read and merged on your device, not in our cloud. Below are the steps for the three big providers.

Google Calendar

  1. Open calendar.google.com.
  2. Click the gear icon at the top right, then Settings.
  3. In the left sidebar, click the calendar you want to add.
  4. Scroll down to Integrate calendar.
  5. Copy the Secret address in iCal format.

That is the URL you will paste into manyCalendars. It ends in .ics.

Tip: the secret address is private to you. Anyone who has it can read that calendar, so do not paste it into shared docs or chat. If it ever leaks, click Reset next to the address in Google settings to invalidate the old URL.

Outlook

  1. Open outlook.live.com/calendar, or your work Outlook on the web.
  2. Click the gear icon, then View all Outlook settings.
  3. Go to Calendar, then Shared calendars.
  4. Under Publish a calendar, pick the calendar and set the permission to Can view all details.
  5. Click Publish, then copy the ICS link.

Many corporate tenants disable calendar publishing entirely. If the publish option is missing or grayed out, that is IT policy, not a bug. In that case, browser-tab calendar sync on Pro can read the calendar straight from the tab you already have open, with no export needed.

iCloud

  1. Open icloud.com/calendar, or the Calendar app on your Mac.
  2. Click the share icon next to the calendar you want to add.
  3. Turn on Public Calendar.
  4. Copy the link. It starts with webcal://.
  5. Change webcal:// to https:// at the start of the URL. The rest stays the same.

iCloud only offers public links, not secret per-person ones. The URL is long and unguessable, but treat it with the same care as the others.

Paste it into manyCalendars

  1. Click the manyCalendars icon in your toolbar.
  2. Click Add Calendar, then choose URL.
  3. Paste the ICS address.
  4. Give the calendar a name and a color so you can spot it on the grid.
  5. Save.

Your events appear right away and the feed refreshes automatically from then on. You do not need to keep the provider's tab open, and you never have to paste the URL again.

Tip: providers cache published feeds. A brand new event can take a little while to show up in an ICS feed, sometimes a few hours on Outlook and iCloud. If something looks stale, that delay is on the provider's side, not in manyCalendars.

Troubleshooting

The URL is rejected. Check that it starts with https:// and ends in .ics. A webcal:// link needs the prefix swapped first, as described above.

The feed loads but events are missing. For Outlook, make sure you published with Can view all details. The lighter permission levels strip event titles and times down to busy blocks.

Still stuck? Email support@manycalendars.com and include which provider you are connecting. Never include the secret URL itself in the email.

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