Tutorial: Detecting Conflicts Between Google and Outlook Calendars

The most common multi-calendar setup

If you work with multiple clients, chances are you have at least one Google Calendar and one Outlook calendar. Maybe Client A runs Google Workspace and Client B runs Microsoft 365. These two calendars live in completely separate ecosystems with no native way to share free/busy data between them.

manyCalendars solves this by pulling both calendars into a single view and automatically detecting conflicts between them. Here is how to set it up.

Step 1: Add your Google Calendar

You have two options for adding a Google Calendar to manyCalendars.

Option A: ICS feed. In Google Calendar, go to Settings, find the calendar you want to add, and scroll to "Secret address in iCal format." Copy that URL and paste it into manyCalendars's "Add Calendar" dialog. Select "ICS Feed" as the source type. manyCalendars will poll this feed periodically and import events automatically.

Option B: Tab Sync. Open Google Calendar in a browser tab and navigate to the week you want to capture. In manyCalendars, click "Add Calendar" and select "Tab Sync." Choose the Google Calendar tab from the list. manyCalendars reads the visible events directly from the page. This method gives you real-time data without waiting for feed updates.

For most users, Tab Sync is the better option. ICS feeds from Google can lag by several hours, which means recently-booked meetings might not appear until it is too late to catch a conflict.

Step 2: Add your Outlook calendar

Tab Sync from Outlook Web App (OWA). Open Outlook in a browser tab (outlook.office.com or outlook.live.com) and navigate to the calendar view. In manyCalendars, click "Add Calendar" and select "Tab Sync." Choose the Outlook tab. manyCalendars will read the events from the page.

ICS feed (if available). Some Outlook configurations allow you to publish your calendar as an ICS link. If your organization supports this, you can find it under Calendar Settings > Shared Calendars > Publish a Calendar. Copy the ICS link and add it to manyCalendars. Note that many corporate tenants disable this feature, so Tab Sync is often the only option.

Step 3: Watch conflict detection work

Once both calendars are loaded, manyCalendars automatically compares every event on your Google Calendar against every event on your Outlook calendar. When two events overlap in time, both get a red outline and an exclamation badge.

Example: Your Google Calendar shows "Client A Standup" at 10:00-10:30 AM. Your Outlook calendar shows "Client B Sprint Planning" at 10:00-11:00 AM. manyCalendars immediately flags both events with a red conflict indicator. The topbar shows "1 conflict" and both calendars in the sidebar display a conflict count.

You see this the moment you open manyCalendars. No manual comparison needed. No switching between tabs to check. The overlap is right there, highlighted in red, impossible to miss.

From here, you can decide which meeting to reschedule, or use manyCalendars's availability export to propose alternative times to one of the meeting organizers.

Keep it updated

If you are using Tab Sync, sync again whenever your schedule changes significantly. If you are using ICS feeds, manyCalendars polls automatically on a schedule you configure. Either way, the conflict detection runs every time new data comes in.

The goal is simple: never be surprised by an overlap again. Two calendars, two providers, one unified view, zero guesswork. Get started with manyCalendars and connect your first Google-Outlook pair in under two minutes.