How to Connect Multiple Calendars to Microsoft Copilot

In our previous article, we explained how to connect multiple calendars to Gemini, covering supported calendar providers, limitations, and solutions to allow Gemini to read availability from all calendar providers, including Outlook and iCloud Calendar.

Similar to how Google is trying to integrate Gemini into the Google Workspace ecosystem, by allowing users to connect their Google Workspace to Gemini, including calendars, email, etc, Microsoft is doing the same with Copilot.

What differentiates Microsoft Copilot from Google Gemini is that Microsoft Copilot integrates with Outlook and Google Calendar by default, unlike Gemini, which only works with Google Calendar.

This might sound like good news (and it is), but Microsoft Copilot suffers from almost the same issues as Gemini when it comes to connecting multiple calendars and reading the availability from all of them.

In this article, we’ll learn how to make Microsoft Copilot read availability from multiple calendars, including Google Calendar, Outlook, and iCloud Calendar.

What calendar providers does Microsoft Copilot integrate with?

Microsoft Copilot integrates with Google Calendar and Microsoft Outlook. You can log in to Microsoft Copilot and connect each provider separately.

How to connect Google Calendar to Microsoft Copilot?

To connect a Google Calendar to Microsoft Copilot, follow these steps:

1. Sign in to Microsoft Copilot.
   
2. Click on the profile picture icon on the top left of the page.
   
3. Click “Connectors”
   
4. Click the “Connect” button on the right of “Google Calendar”
   
5. Follow the instructions on screen to connect your Google Calendar.

How to connect Outlook to Microsoft Copilot?

To connect an Outlook Calendar to Microsoft Copilot, follow these steps:

1. Sign in to Microsoft Copilot.
   
2. Click on the profile picture icon on the top left of the page.
   
3. Click “Connectors”
   
4. Toggle the switch on the right of “Microsoft Outlook”. Note that you’ll see a “Connect Button” if you’ve signed up with Google. In my case, I’ve signed up with Outlook, so Microsoft Copilot already has access to my Microsoft Outlook account.
   

What limitations does Microsoft Copilot have when reading calendar events?

It’s great that Microsoft Copilot allows you to connect your Outlook and Google Calendar, but it’s not without flaws:

• Microsoft Copilot allows you to connect to only one Microsoft Outlook account. When clicking “Connect”, you’re redirected to the Microsoft OAuth screen, where you grant access to your calendar. Alternatively, if you’ve signed up with Microsoft, you’ll see a switch to enable or disable the Microsoft Outlook connection. If you’d like to add another Microsoft Outlook Calendar, you’ll notice that there is no such feature.
• Microsoft Copilot can only read events from the primary Microsoft Outlook Calendar. After completing the connection and starting to ask questions, you’ll notice that Microsoft Copilot doesn’t reference any events from secondary Outlook calendars. I’ve conducted a series of tests by creating events in secondary Outlook Calendars, and Microsoft Copilot never referenced those. My conclusion is that Microsoft Copilot doesn’t read events from secondary calendars.
• Microsoft Copilot allows you to connect to only one Google Calendar. Similar to the Outlook integration, you can only connect one Google Calendar to Microsoft Copilot. There is no option to connect a second or a third Google Calendar account.
• Microsoft Copilot can only read from the primary Google Calendar. The issue I noticed when asking questions about my Outlook Calendars persisted with Google Calendar. Microsoft Copilot wasn’t aware of my secondary Google Calendars, and it seemed like it couldn’t read or write to those calendars.
  
  I even asked Microsoft Copilot to list all the calendars it has access to, and it only listed the primary calendars.
  
  
  
  
  I also asked Microsoft Copilot to list the secondary calendars in each account, but it only listed the primary calendars and stated that "No secondary calendars (like shared, group, or custom calendars) are visible at the moment.”
  
  
  
  
• No support for iCloud Calendar. Besides the connectors for Google Calendar and Outlook Calendar, there is no built-in support for iCloud Calendars.

How to make Microsoft Copilot read and analyze events from multiple calendar providers?

Considering the Microsoft Copilot limitations, a) it can only connect to one calendar provider, and b) it can only read the primary calendar; secondary calendars can’t be accessed, the most viable solution would be to sync all your calendars into a Microsoft Calendar and connect that calendar to Microsoft Copilot. We could also sync all calendars into a Google Calendar, for that matter, but we chose Microsoft Outlook, as Microsoft Copilot is a Microsoft product, and I reckon they work better together.

In simpler words, we need to copy all events from all calendars into a Microsoft Outlook account and connect that Microsoft Outlook account to Microsoft Copilot.

You could manually copy events from all your calendars to Microsoft Outlook, but it takes time, and it’s not ideal, as you can’t stay on top of your calendars 24/7. That’s why we recommend using OneCal to automate this process.

OneCal is a calendar sync tool that syncs Outlook, Google Calendar, and iCloud Calendar in real-time, automatically.

The illustration below shows how OneCal would fit into the solution:

TL;DR:

Gemini (1) can only read data from one primary Outlook Calendar (2).

OneCal (3) automatically pulls in events from your external calendars (4–6), like iCloud, Google Calendar, or other Outlook Calendars, and keeps them synced in real time to your primary Outlook Calendar (1).

This way, Microsoft Copilot indirectly gains visibility over all your calendars through OneCal, without needing direct access to each provider.

In this image:

• Microsoft Copilot (1): Reads and analyzes events from the primary Outlook Calendar (2).
• Primary Outlook Calendar (2): The primary Outlook Calendar that contains all the events, including events from Google Calendar, iCloud Calendar, or any other Outlook Calendars. This is the calendar that OneCal (3) syncs all the other calendars to.
• OneCal (3): The software that keeps the calendars in sync. You can connect multiple calendars to OneCal, including secondary calendars, shared calendars, and instruct it which ones to keep in sync. After setting up the configuration, OneCal keeps the calendars in sync, in real-time, automatically.
• (4), (5), and (6) External calendars: The elements tagged as (4), (5), and (6) are external calendars like Google Calendar or iCloud Calendars that you need Microsoft Copilot to read events from. Those are the calendars that OneCal takes events from and syncs them to your primary Outlook Calendar (2). This illustration has another Outlook Calendar (5), as using OneCal, you can also sync Outlook Calendars from different Microsoft Accounts.

Using OneCal, you can sync as many calendars as you like, so you can make Microsoft Copilot read the availability of multipl Outlook, Google Calendars or iCloud Calendars.

Here are some guides that can help you sync different calendar providers:

• How to Sync Outlook and Google Calendar: In case you want to sync your Outlook Calendar to Google Calendar.
• How to sync iCloud Calendar with Google Calendar: For syncing iCloud Calendar with Google Calendar.
• How to sync Google Calendars: For syncing Google Calendars within the same Google Account or within different Google accounts.

Make Microsoft Copilot read and analyze Google Calendar, iCloud Calendar, using OneCal

OneCal is the most reliable calendar synchronization software in the market, trusted by thousands of professionals around the world. The process to get your calendars synced is very easy, and the customer support is there to help you out in case you need help.

Sign up for a free OneCal account, no credit card or commitment required. Using OneCal, you can use Microsoft Copilot to the fullest.

FAQ

1. Does Microsoft Copilot support shared or group calendars?

Not yet. Copilot only reads events from the primary calendar of your connected account. Shared, group, or secondary calendars (such as project calendars or delegated calendars) are currently not supported, even if you have permission to view them.

2. Can I connect more than one Google or Outlook account to Copilot?

No. You can only connect one Google Calendar and one Outlook Calendar at a time. If you use multiple work or personal calendars, you’ll need a sync tool like OneCal to combine them into a single primary calendar that Copilot can read from.

3. How does Microsoft Copilot compare to Google Gemini for calendar management?

Both tools aim to integrate deeply into their ecosystems: Microsoft Copilot for Microsoft 365 (Outlook, Teams, OneNote) and Gemini for Google Workspace (Gmail, Calendar, Drive). The main difference is that Copilot supports both Outlook and Google Calendar, while Gemini only works with Google Calendar. However, both face similar issues with handling multiple calendars or secondary ones.

4. Can I connect my iCloud Calendar to Microsoft Copilot?

No, there’s currently no direct integration between Microsoft Copilot and iCloud Calendar. However, you can sync your iCloud Calendar with Outlook or Google Calendar using OneCal, which enables Copilot to indirectly access your iCloud events.

5. Is Microsoft Copilot free to use?

There’s a free version of Copilot available, but advanced features like integration with Outlook, Excel, and Teams require a Microsoft 365 subscription with Copilot included.

6. Can Microsoft Copilot summarize or analyze meetings from my calendar?

Yes, if your events contain meeting details or Teams links, Copilot can summarize them, extract topics, and generate follow-ups.

6. Is there a security risk in syncing all my calendars together?

If you use a trusted service like OneCal, your data remains encrypted and protected. OneCal uses secure OAuth-based connections (the same method Google and Microsoft use for authentication) and does not store calendar content, it only facilitates syncs between your accounts. Please read the OneCal Data Security page for more.